Two Neulparan High School students, Kim Ki-bum and Donghae, find themselves drawn into a troubling pattern: a string of pranks aimed at the neighborhood’s popular “flower boys” from nearby schools. On Valentine's Day, February 14, Lee Sung-min’s character, Sung-min, a handsome student at Garam High School, is attacked on his way home, a bag of faeces hurled at his face, the incident fueling a growing sense of fear and curiosity among the student body. The attacks continue in the following months, each one seemingly targeting a new star from a different school.
On March 14, Hangeng, a basketball standout from Geosang High School, becomes the latest victim, again by the same shocking method, and then on April 14, Nadam High School’s rock vocalist, Yesung, joins the list. As the incidents multiply, Kibum’s blog posts gain traction, and his readers start to speculate about a pattern. He predicts that the next victim would come from their own school, narrowing the suspects to Choi Si-won (the student body president), Kim Hee-chul (the fashionable head of the dance club), or Han Geng (the judo captain who rose to prominence with a single move, ippon seoi nage).
The case captures mainstream media attention and earns a nickname: Attack on the Pin-up Boys. With the spotlight comes a surge in popularity for the victims. Sung-min lands a modeling contract for three years, and Yesung makes his mark as a solo artist, releasing a successful album. Heechul and Kangin jump into the publicity machine as well, posting alluring pictures on their blogs in hopes of becoming the next target.
As May arrives, anticipation runs high. Kibum and his classmate Donghae are stuck in an extra class due to poor grades, but Donghae manages to slip away to continue the investigation. The next day, Kibum learns that Si-won claimed to have been attacked the day before. After checking the claim, Kibum concludes the attack was staged by Si-won, differing in its execution. Heechul and Kangin press on with their campaigns, trying to stay in the public eye as the next target.
Donghae, a member of the dance club, reveals to Heechul that the perpetrator’s next strike is likely near the garbage dumping ground between 9 and 10 pm. When Heechul heads to the area, he encounters Kangin, and the two realize they’re pursuing the same idea. Meanwhile, Donghae, tailing Kibum, accuses him of being the culprit. Kibum admits his fault but, rather than exposing him, Donghae proposes an alternative plan.
The following day, Donghae becomes the newest and final victim of the serial attacks, drawing a close to the immediate wave of intrigue. Interest in the case wanes over the ensuing months without further incidents. In the aftermath, Donghae asks Kibum where the faeces originated, but Kibum refuses to reveal the source, leaving the mystery unresolved and the door open for speculation.
