Soo Ji, Si Hyun and Se Joo are best friends; they disclose a teacher's affair by airing the footage on a big screen during their graduation ceremony; Soo Ji's first love, Lee Ki Young, tells her some hurtful words.

After the graduation, Si Hyun and Se Joo decide to go clubbing; Si Hyun meets a woman and shares a kiss with her; Soo Ji decides to take revenge on Ki Young by targetting Park Hye Jeong and Eun Tae Hee.

Soo Ji's mother and Si Hyun's father make an official announcement about their engagement; Soo Ji, Si Hyun and Se Joo find out about the adults' relationship; the three musketeers try to find a way to stop their parents from getting married.

To prove Si Hyun's sincerity towards her, Soo Ji tells him to participate in a game of seduction; Si Hyun tries his best to make Tae Hee like him, but Tae Hee won't budge; Soo Ji visits her mother's office and begs her not to get married.

Si Hyun, Soo Ji and Se Joo discuss how Si Hyun will seduce Tae Hee; Si Hyun tries to make Tae Hee feel like it is fate by purposely running into her often; Tae Hee does not easily waver.

Si Hyun helps Tae Hee out at a nursing home; Tae Hee sees a generous side to him that she never knew about; she tells him that she will not date him, and Si Hyun asks if she dislikes him that much; Si Hyun feels a strange emotion toward Tae Hee.