In Genie High School, Jae-hee encounters Tae-joon, who is repulsed by her behavior, and befriends soccer athlete Cha Eun-gyeol (Lee Hyun-woo) after a brief brawl with an aggressive muscle boy in the bathroom. Ha Seung-ri (Seo Jun-young), dormitory captain of Dormitory 2, assigns Jae-hee as roommates with Tae-joon. Disgusted of having a roommate, Tae-joon challenges Jae-hee to score a goal in a soccer game so that she will be admitted as his roommate. Jae-hee is injured in the match and is brought to the school infirmary, where the infirmary custodian Teacher Jang Min-woo (Ki Tae-young) becomes the first to discover Jae-hee's true identity. Jae-hee reveals her purpose of coming to Genie High School and pleads for her secret to be kept, to which Teacher Jang, realizing Jae-hee's resolve, hesitatingly accepts.
Jae-hee begins to adapt with the school and her schoolmates, gradually gaining Tae-joon's favor and of the entire Dormitory 2 when she won in a marathon match. A confused Eun-gyeol begins to doubt his sexuality when he begins to feel attracted to Jae-hee, not knowing she is a girl. Tae-joon, who already have hints on Jae-hee's real gender, saves her from being raped during a trip at Seung-ri's place.
When Jae-hee's older half-brother, Daniel Dawson (Julien Kang), comes to Korea, he finds out what his little sister is doing. Daniel soon decides to make Jae-hee leave the school. Jae-hee and Daniel argue in her and Tae-joon's room, and Tae-joon overhears their conversation, and discovers Jae-hee's secret. Tae-joon sends her out, but he later appreciates her candid efforts in helping him in his athletic career when he discovers a video email that she sent to Canadian high jump coach Mr. Holten, which also contains a brief narration of Jae-hee's bitter life in America and her anticipation to see Tae-joon jump again. Tae-joon pleads Jae-hee not to leave him behind. Teacher Jang, then, convinces Daniel Dawson to trust Jae-hee and to let her stay in Genie High School.