In the opening scene, Casey (Skylar Astin) and Miller (Miles Teller) walking through the middle of campus, naked with only a tube sock covering their genitals. Their butts have been branded with a sorority symbol. "None of that ever happened," Casey tells Miller. "None of it," Miller says agreeing.
ONE DAY EARLIER
We see Miller in a taxi talking to the driver about why he traveled to the university. He and Casey have come down to surprise their old high school pal Jeff Chang (Justin Chon) for his 21st birthday. Miller opens a beer in the backseat which the driver notices but Miller denies having it. They pick up Casey and the two of them start talking. Miller asks about Casey's family and more specifically his sister. Casey tells Miller that every time he asks about his sister, he knows that Miller wants to have sex with her. Casey points out that she is 16 and thus underage. Casey asks how would Miller like it if he would say he wanted to sleep with his sister. Miller says his family would consider it an honor. Miller tries to make a bet for five dollars that he will sleep with Casey's sister before Casey could with Miller's. "I'd fuck my sister first before I sleep with your sister," Casey says. Miller said he'd actually pay him to sleep with his own sister.
"Can we stop the talk about the sister fucking!" the exasperated cab driver screams. He drops them off at Chang's address and tells them to get out.
Casey and Miller head up the steps and see The Chief (Russell Hodgkinson) dancing around high. Miller tells Casey if they don't look like that in 2 hours, they have failed at life.
They ring on the door, and Chang shows up. He is surprised, but happy to see his old friends. They explain why they came, and Chang tries to explain that he can't. They get inside his room, and Chang explains that he has an important med school interview tomorrow that his father set up. Miller insults Dr. Chang (Francois Chau), only to find him right behind him. He recognizes the two and chastises his son for still surrounding himself with people like Casey and Miller. He tells his son that he will be at the house at 7:00 am to pick him up for his 8:00 am interview and not to embarrass him. Dr. Chang leaves.
Chang says that was what he was trying to tell them; he couldn't go out tonight. He asks Miller if he could reschedule for tomorrow. Miller says no because he has tickets for a concert the next day. That is beside the point; Miller tells Chang that his 21st birthday is a rite of passage, the time where he can show every bar bouncer that though he still looks like a "9 year old girl" he is of legal age. Chang says he can't do it. Miller then tells him if he doesn't come with them, he will stay outside with an air horn and blast it all night so he can't sleep. Chang finally agrees, but only to one drink.
Of course, that doesn't happen. When we see them again, Chang is already smashed and getting worse. Chang is happy though and hugs Casey and Miller and thanks them for coming down to see him. Miller asks about the Sidewinder festival, and Chang is happy to think about it. Being pre-med he hasn't had time to write music, play music, or even listen to music. Miller asks Casey but Casey reveals he already has a job lined up for the summer at a Wall Street firm. Chang congratulates him, but Miller can't believe he has a job already and can't even enjoy his last summer before settling into adulthood.
A friend of Chang's, Nicole (Sarah Wright) shows up, and she congrats Chang for his 21st. Miller is taken by her and asks straight up who would she rather sleep with it; him or Casey. She picks Casey, so Miller takes Chang away to play darts to let Casey talk to her.
Chang and Miller play darts. Miller voices his concerns for Casey's attitude.
Nicole tells Casey she is going to South America for Spring Break. Casey mentions his internship, and Nicole balks at spending his last Spring Break working. She points out that everyone in the bar will be married with kids and in crappy jobs in 10 years, and they need to do as much crazy stuff as they can NOW. Casey says he does some crazy stuff. Like jumping into the pool after eating. Nicole laughs.
Miller is still complaining about Casey. Chang doesn't see what the problem Miller sees. Chang accidentally throws a dart without looking, piercing Randy (Jonathan Keltz) in the cheek. Randy obviously is not happy with that, and Chang is embarrassed and horrified by what he did. He tries to take a look, telling Randy he is a med student, but Randy will not listen, being pissed off. Miller tries to tell Randy it was an accident, and they're sorry. Randy responds that accidents have all the time, and takes a bar stool and slams it into Chang hard. Chang and Miller realize they need to get out of the bar now.
Casey and Nicole are still talking. It's obvious Nicole is interested, and if Casey has a little more game, he could get somewhere. However, Miller and Chang pull him away from her and out of the bar. Nicole smiles and waves him goodbye.
Casey asks what was so important that he had to pull away from Nicole. Miller tells him he wouldn't have closed with her anyway. Casey says they should take Chang home, but Miller see there are over 20 bars in the area and doesn't want the night to end yet. Chang notices Galloway's, a bar that carded him like crazy and he wants to get in now. He goes up to the bouncer, and the bouncer insults him. Chang pulls out his ID. "Twenty one...BLACKJACK MOTHERFUCKER!" Chang says. The bouncer just tells him to go inside. "Where's all the white women at?" Chang calls out. Miller and Casey follow behind him.
A bar montage ensues in which Chang drinks more, break dances on the dance floor, exposes himself to a bar full of women then proceeds to urinate on them and rides a mechanical bull before projectile vomiting.
Casey and Miller realize they have to take home Chang home for sure then. Problem is they don't know where he lives. However, Casey remembers Nicole. Miller says to give it up, he can't close, but Casey means Nicole knows Chang so he should know where he lives. Plus, he saw her sorority sweatshirt so they can just go find her.
Casey and Miller drag Chang across the university looking for the sorority. They check Chang and find a revolver on him. They are seriously freaked out by him having it. Miller jokes about wanting to kill a squirrel.
They stop at what they believe is the right sorority and ring the bell. Two girls answer and write on a white board there are no visitors after 11:00 pm. Casey tries to ask about Nicole, but the girls shut the door in their faces. Casey doesn't know what to do, but Miller has a plan. Finding an open window around back and the three get inside. They get inside and notice a banner proclaiming the building a Latina sorority. Miller and Casey are confused (they are obviously in the wrong place). They drag Chang with them, but Chang starts to make noise. They tie him to a toilet so they can search for Nicole.
Miller and Casey look around and realize they are in the wrong place but keep looking until the hallway hits a dead end. Hearing someone and having no choice, they drive into another room. The two girls in the room jump up blindfolded and proclaim they are ready for their punishment, mistaking them as their Pledgemistress.
Chang meanwhile is struggling in his restraint. A woman comes in and mistakes him for a girl. He continues to make noise and breaks free from his restraints. The girl finally notices it is Chang and watches in bewilderment as he eats a tampon, mistaking it for candy.
Meanwhile, the two pledge girls say they are ready to be spanked, so Miller goes with it and starts spanking him. He speaks up, and the girls start to go suspicious. Miller said the Pledgemistress told to be there and if they object she will find out. The girls plead for him not to say anything and asks what is next. Miller said they should make out. Though weirded out, they do with even Casey, who has been lightly objecting Miller's behavior, unable to stop himself from watching.
The girl in the bathroom comes out and attacks Chang, using rapist defense techniques. She screams about an intruder and the two pledge girls take off their blindfolds and look at Casey and Miller. Realizing they have been busted, they quickly run into the bathroom and lock it. They are freaked out about the group of Latin sorority sisters trying to kill them. They climb out a window onto a balcony just as the girls are breaking through the door with a golf club. They swing Chang onto the pool cover that bounces him into a rose garden. "Oh my god, did we just kill Jeff Chang?" Miller asks (a running gag; throughout the film they never call him by just his first or last name but his full name). They have no time to think about it as the sorority girls are about to get them. Casey notices Nicole's sorority just before they jump themselves.
Casey and Miller get Chang to Nicole's sorority and force themselves inside. Nicole finds them and helps them get the thorns out of Chang's body. They ask if she knows where Chang lives, and she says she doesn't. She only took remedial science with him, and he rarely talked to anyone. Miller and Casey realize what she is saying and balk; Chang is great at school. However, Nicole tells them the opposite; he's failing Science and isn't doing so hot in most of his classes. Casey and Miller are stunned as Chang didn't tell them any of this. Nicole tells them a friend of hers, Randy, has all the student addresses since he is a cheerleader and offers them a ride to a pep rally where he will be. They take her up on that offer.
And with good reason. Casey and Miller see that the Latina sorority is looking for them everywhere. They see Nicole's car show up and are horrified that it is a very small car. Nevertheless, having no choice, they rush it, and pile themselves in there before the Latin sorority can get to them. The head sorority sister tells the others to "Get the Van."
Nicole drives the three to the pep rally with Chang passed out on the dash.
When they get there, Casey asks if Nicole wants to go with them, but she says she is going to a party. She also mentions Randy is her boyfriend, something she hadn't brought up before. Casey is crushed and Miller ribs him about it.
Dr. Chang hears the sorority girls searching outside and asks what is going on. One of them shows him a photo of Miller and Casey and mentions they had an Asian boy with them. Dr. Chang is enraged and plans to find them.
Miller and Casey find Randy only for Miller to realize that he is the same guy Chang accidentally hit with a dart. Randy is obviously not happy to see them. Casey tries to ask nice about Chang's address, but Randy wants to be a tool. Miller having enough, pulls out the gun and asks for Randy's phone. Randy thinks the gun is fake, so Miller shoots it in the air. That however, causes a live buffalo brought in for the pep rally to be startled and start charging and attacking people. Miller and Casey escape with Chang in a golf cart and Randy gets trampled by the buffalo.
Casey finds Chang's address, and they begin to drive there. Miller has been enjoying their night saying he misses college and that he almost regrets dropping out. Casey looks at him in shock and asks when this happened. Miller admits he dropped out two years ago and has been working at a gas station. He thought that he wasn't good, enough unlike Chang and Casey. Casey tells him he is crazy as he is the smartest person he knows and he should go back to school. Casey then concedes that perhaps he can get away for a week or two to go to the Sidewinder festival which makes Miller happy.
They get to the address to find a dorm housing. Casey realize it is a old address. They pull Chang in and see a full raging party is happy. They knock on a door or two before finding Sally Huang (Samantha Futerman) and asks if she knows Chang. Sally thinks they are being racist before realizing that she actually knows him. She tells them that Chang kept to himself and eventually move out when he was arrested. Casey and Miller are freaked out as they knew nothing about that. They press for more info, and Sally says his old RA, PJ, might know something. She tells them if they see him, to tell him to keep it down since she has field hockey in the morning. She then shuts the door in their face.
Miller and Casey find out if they want to get to PJ, they have to beat each drinking game on 8 different floors to get to him. They plop Chang down on a couch with some stoners and get to work. First they beat some Serbian beer pong players, making plenty of Rocky and rapist jokes at them. A montage ensues as they conquer each floor before making it to the last one. It is when Casey reunites with Nicole, and they play the final drinking game together with Miller. Nicole mentions a favorite vacation spot of hers and Casey says he loves it there too. The moment is broken however, when Nicole finds out Randy has been hurting by the buffalo and the reason he hasn't responded to her was because his phone was stolen (Miller took it). Nicole leaves.
The stoners, seeing how messed up Chang is, decide to mess with him. They strip him naked, glue a teddy bear to his penis, places a bra on his chest and cover him with graffiti.
Miller and Casey make it to PJ. Miller is less than impressed with the final floor and their prize of gold beads. PJ bemoans his lack of funds and mockingly says he'll try better next time. Casey asks about Chang and PJ reveals he was arrested for attempted murder. The two of them are stunned. They leave, realizing they need to get him home. However, they see him outside, naked and making a further fool of himself. Casey tries to calm him down, but Chang whispers, "You'll never take me alive," and runs off.
Casey and Miller run off and pursue him. Chang meanwhile, jumps on a bunch car before a cop car sees him. The cop tells him to "Get down, now." Chang begins to dance, taking the command literally." Just as Casey and Miller are going to intervene, Dr. Chang shows up and confronts him, asking them where his son is. They lie as his son is being arrested behind his back literally. Dr. Chang tells them they waste their lives being drunken fools and drives off. Casey and Miller breathe a sigh of relief and go to track him down.
They go to the police station only to see Chang had been transported to the hospital wing of the campus. A woman, Cara, offers to escort them across campus. Walking them, a van pulls up. Cara is a member of the Latina sorority. They pull masks over Casey and Miller and kidnap them.
When they come to they are surrounded by robed members of the sorority, buck naked saved for their tube socks on their genitals. They are going to be punished for breaking in, embarrassing their pledges and destroying their rose garden. They are swiftly found guilty. First, they are spanked by paddles by the girls they did it to earlier. Next, since they made the girls kiss each other, they are ordered to, as well. Casey and Miller balk at that, but the leader says if they don't they will be branded with the sorority logo on their butts. Casey freaks out, not wanting to be branded, saying he won't be able to be buried right (he's Jewish). Casey and Miller eventually go with it, awkwardly.
Cut to the next morning, where the movie began. The sorority branded them anyway.
As they walk, Casey calls Miller out on his bullshit; he forced Chang to go out and get drunk and caused everything. Miller says Chang is an adult and made his own choices. Besides this is what friends do for each other for their birthdays. Casey, angry at him, says they are not friends. Not anymore. Miller tells him if they are going to be honest, he is tired of Casey's crap too. He thinks it is stupid that Casey is so ready to settle for monotony of adulthood. Casey says he is growing up, but Miller says he has forgotten how to be young and have fun. They have a naked fight in the middle of the quad due to their fighting.
Later, they reach the hospital and are given hospital scrubs to have clothing. Nicole comes out and spots them. She says she went to check on Randy after his attack, but he acted like an asshole so they broke up, it being a long time coming. Nicole says she will be leaving on her trip in a few hours and waits for Casey to say something. He doesn't, scared, and so she leaves, saying goodbye. Casey kicks himself for being too chicken.
They find out by the head nurse that Chang will be held 24 hours. They grab the file from her and find out that not only Chang has been there numerous times, his attempted murder charge was actually an attempted suicide. Casey and Miller are shocked at how little they know about their friend. The nurse kicks them out.
Casey and Miller sit on the hospital steps and realize how bad friends they had been if Chang couldn't even feel like he could call them to tell them what was wrong. They decide to help Chang get home on time. They notice The Chief walking out, and he tells them he took some LSD and wound up dancing outside his house all night (also that he is actually a professor at the University). Casey realize that they had probably passed by Chang's house numerous times during the night (as The Chief lives next door) and didn't realize it. They get The Chief's address and go get Chang so he will be ready for his interview. Busting through the hospital rooms they find Chang and decide to slowly drop him out of the window on top of the pep rally SUV. They change their mind, but it is too late. They can't pick him up so he drops two to three stories onto the hood of the car. "Did we just kill Jeff Chang again?" Miller asks.
They get outside to find the SUV missing. Chang shows up having stolen it just as Randy shows up and notices. The three of them pile in, and Chang drives off.
However, Chang is still obviously drunk and drives erratically, sometimes not even looking at the road. "I feel real alert, like Spider man," Chang notes, seconds before toppling a half dozen parking meters. Casey and Miller are scared, while Chang cuts through the university with a police car not far behind. Miller thinks they are going to die and admits that he wants to go back to school, he wants to make out with a black chick, and that he wants to really fuck Casey's sister. Chang hears the dropped out of school part and looks back at him. Miller tells him to watch the road. They eventually fish tail over a hill, with the car doing a 360 turn several times before landing right side up on a lower road with the police car unaware. "Maybe I shouldn't drive," Chang says.
Having twenty minutes or less to make him presentable, the three race home and get him showered and cleaned up. Having no choice, they yank the teddy bear off Chang's penis, causing him immense pain. "I think we just circumcised Jeff Chang," Casey says. They get him in a suit and tell him he's ready. Chang says he doesn't know if he can do this; he doesn't want to be a doctor, and he's failing all the courses needed for it anyway. Miller blurts out that they know about his suicide attempt. Chang says he didn't actually try to kill himself; he had been studying for 72 hours straight, coked out on pills to help him focus and he started to hallucinate in his room, and the gun went off.
Miller and Casey tell him that he needs to be honest with his father. "Tell the truth?" Chang says. "Guys that is so white."
They hear a knock at the door, and thinking it is Dr. Chang, Chang opens it. However it is Randy who punches Chang to the ground with a baseball bat and starts destroying things for the earlier dart incident. Dr. Chang shows up and asks Randy who the hell he is. Randy threatens Dr. Chang and tells him his son won't be making that interview. Seeing it coming, Chang, Miller, and Casey wince as Dr. Chang takes the bat and beats up Randy. He then tells his son to come with him.
Chang finally stands up to his dad, and says he doesn't want to be a doctor. Dr. Chang seemingly understands, then says he understands that he raised a worthless piece of shit son. Miller, having enough, punches Dr. Chang for bad talking his son like that. Chang tells his father to leave, and he does. Randy gets back up and tells Chang is father is a dick too and apologizes for being an asshole. Though weirded out, he accepts Randy's apology and Randy and his crew leave peacefully.
Chang feels great as he can now do what he wants in life. Chang tells his friends that he wants to start doing music again, and really enjoy life for once as now every decision will be his own. Casey gets an epiphany and tells them he'll see them later, running to catch Nicole. "You're ruining the moment, dick," Miller screams after him. Chang sighs and notes, "My fucking dick hurts."
Casey sees Nicole's car pull away and is sad to have just missed her. Nicole calls out to him nearby though; she is letting her friend borrow it while she is away. Nicole asks if he has something to tell her. Casey says yeah and kisses her. They proceed to make out.
3 MONTHS LATER
Casey, Nicole, Miller, and Chang are at the Sidewinder festival. Miller is making out with hippie girls like he wanted, and Chang apparently has a girlfriend. Casey and Nicole are a couple, as well. Miller says he has a meeting with the college board about getting back to school so they can't go too crazy. Casey smirks and Chang says he is the "little baby" tonight.
Cut to the next morning with Miller with crutches due to a broken foot, hair highlighted half red, and wearing a jumpsuit with "Coroner" on the back, late for his interview. He gets into the office with the professor he is meeting only to realize it is The Chief. The Chief laughs and says Miller looks like shit and Miller laughs at his good fortune; at least with The Chief, he has someone who understands the ideal of a good time and he should still have a good shot of getting back into school.