The cast of characters, who are exceptionally attractive and/or genuinely lovable, would probably make this movie worth watching in any case. Fortunately, in addition to the eye-candy, this movie involves quite decent acting and very well-orchestrated humor. It's based on the usual run of misunderstandings that thwart the quest for true love, but done in a way that pokes fun at the whole overly dramatic, soap-operatic response often used in other movies, especially in terms of peer support and psychoanalytical "therapy." Quite often in Asian language movies the English subtitles can defeat the dialogue but in this case the subtitles were obviously done by someone with an excellent command of English. The only bizarre issue was that every letter J was turned into a K. So the main character is looking for a summer "kob" and denies feeling "kealous." Not something that really matters, but strange nonetheless.
I think I missed the "formula 17" meaning,unless it refers to the one boy's age, but there is a trigonometric identity featured for fans of mathematics.
If you want a light, feel-good experience, this movie is well worth watching. No ponderous morality or gut-wrenching tragedy, but you do get a lift to your spirits.