Hanjoo Yeo, a reserved and introverted student, has been hopelessly in love with the most popular guy in college, Chanyoung Choi. Despite the unrequited love and constant feelings of regret and humiliation, Hanjoo finds himself unable to end the relationship. But when his father remarries and introduces a stepbrother, Jihyun Yoo, into the mix, strange things start to happen. Nobody seems to notice the tall and handsome stepbrother, and soon, things begin to take an unexpected turn.