Unbalance ×2 (; lit. Unbalance ×2, also Unbalance Unbalance) is a Korean manhwa series written by Dall-Young Lim and illustrated by Soo-Hyun Lee. The series focuses on Jin-Ho Myung, a high school senior, and his romantic relationship with his homeroom teacher, Hae-Young Nah. The manhwa began biweekly serialization in Young Champ magazine in May 2005, and the first volume was released on June 15, 2005 by Daewon C.I. The series had a long hiatus following the release of the ninth volume, and resumed serialization in Young Champ from October 2010 to October 2011. The tenth and final volume was released by Daewon C.I. on January 13, 2012. Unbalance Unbalance was licensed in North America by Infinity Studios, and released the first volume on January 11, 2007. A drama CD was released in Japan in September 2009.
Story
Jin-Ho Myung returns a wallet and cell phone to a beautiful young woman (Hae-Young Nah) in a book shop, little realizing that she would notice that he has already (rather presumptuously) taken 7000 won to buy a book he really wanted. The woman in question is understandably rather upset but decides to consider the money as a loan, which she expects to be paid back.
On the first day of the new school year, he learns, to his horror, that the very same woman is to be his new homeroom teacher. The bad news for Jin-Ho is that she remembers their previous encounter very well.
After a series of misadventures, Jin-Ho and Hae-Young become friends. Eventually, Jin-Ho confesses his feelings for Hae-Young, who is also attracted to him, but is apprehensive because she is older than him and the fact that she is his teacher. All this happens despite the fact that Ji-Soo (Jin-Ho's classmate and Class President) and Jae-Kyung (Jin-Ho's senior and the founder of the school Film Club) are secretly in love with Jin-Ho. Carrie, Hae-Young's half sister from England enters their lives and makes a move on Jin-Ho to taunt her sister. She quickly understands Jin-Ho's love for Hae-Young and supports them.
Hae-Young becomes increasingly conflicted with her feelings for Jin-Ho and dares him to steal her heart by the end of the month, or else she shall leave his life forever. Meanwhile Jae-Kyung breaks up with her boyfriend and resolves to re-enter Jin-Ho's life. She is aware of Hae-Young's love for Jin-Ho and tells her she will steal him. Anguished, Hae-Young admits her love for Jin-Ho who accepts.
Currently, Jin-Ho declines Jae-Kyung's confession of love. Jae-Kyung sorrowfully accepts Jin-Ho's decision on loving Hae-Young instead of her. As Jin-Ho leaves the Film Studies Club room, Jae-Kyung cries in total depression. She soon has a mental breakdown, in which she wears her high school uniform and goes back to school, reminiscing her old days as the president of the Film Studies Club and thinking about Jin-Ho. Jin-Ho soon learns about Jae-Kyung's condition and she is rushed to the hospital. In hopes of bringing her back to normal, the doctor suggests Jin-Ho to support and love her in order for her to recover much faster. Hae-Young later meets Jin-Ho and invites him to her house for a date. Jin-Ho, knowing Jae-Kyung's mental condition, abruptly turns her down much to Hae-Young's dismay. Jin-Ho shares his woes to Carrie, stating that while he certainly loves Hae-Young, he cannot abandon Jae-Kyung because of her mental breakdown. Later Carrie reveals the whole situation to Hae-Young. She visits Jin-Ho and tells him she is willing to fulfil his desire. Jin-Ho once more turns her down and Hae-Young angrily breaks up with him. However, she gets upset and starts sobbing.
Following her break-up with Jin-Ho, Hae-Young decides to resign from her post after the first semester of school. She decides to leave Jin-Ho's life for good. Ji-Soo later asks if Jin-Ho was aware of this fact and if Jae-Kyung was involved, but Jin-Ho denies the involvement of Jae-Kyung and claims that he no longer loves Hae-Young. Ji-Soo later goes to see Jae-Kyung where she overhears her phone call, saying that she had already recovered. After hearing the phone call, Ji-Soo confronts Jae-Kyung, who claims that she doesn't know Ji-Soo, who beats her out of anger for tricking Jin-Ho.
Hae-Young eventually goes to the airport to leave Korea, which she confesses to Caroline that she's happy to be her sister. When she arrives in the UK, she is confronted by Jin-Ho who hands her a device resembling an iPad containing a video message from Jae-Kyung. Jae-Kyung wishes well for Hae-Young and Jin-Ho. Hae-Young tearfully reconciles with Jin-Ho and the two kiss.