Throughout the series, the cast and crew of One Fine Day! hid an animated image of co-creator Marc Morin Jr. in every episode. While originally the public was not told about this, it became a game during the second season for audience members to try a find the "Where's Marc" image.
Kevin Zaideman and Colleen Delany are cousins in real life. Each auditioned and was hired separately by Derek Klein and Marc Morin Jr. without each of them knowing the other was auditioning. It was not until the first read through for the third episode that the two discovered the other was working on the project.
The opening credit sequence for each episode is slightly different that any of the others. Steven wakes up next to a different girl in each episode, and his 'getting ready' sequence varies depending on the girl. In the sixth episode finale, he actually wakes up alone, next to the hidden image of creator Marc Morin Jr. This was done to represent his loss of mojo in the episode. Also in the sixth episode, Christi's sequence changes to show her waking up next to Alexis, to symbolize their new found relationship. This theme was dropped for the series' second season because of a tighter filming schedule and increased size of the cast.
Each episode title is derived from the University of Illinois Housing "Inclusiveness Statement" that all resident advisers are required to post on or near their doors. This holds true for both the first and second seasons.
Students from Michigan State University, the University of Wisconsin, the University of Iowa, Illinois State University, Purdue University, and Eastern Illinois University have all contributed to the University of Illinois production. Residents of Seattle, Washington have also provided assistance and worked on the production. This makes the series the largest independent student media collaboration in the Big Ten.