Kim Aeri has no memories of her past. Her brother’s friends, L, Woohyun and Sungyeol wish to keep it that way. First day at her new school, Aeri meets Lee Hoya. Again. She falls for him. Call it love at first sight? Hoya develops feelings for her. He can’t show it. Aeri regains pieces of her memory. Will she be strong enough to overcome the truth?

Hoya falls in love with Choo Hye-min after they are partnered up for a fan-idol show on Valentine’s Day in 2011. They begin dating more than a year after meeting but two years later, Hye-min realizes that a relationship isn’t working out. She knows Hoya is having a hard time trying to let go. To protect his image as the perfect boyfriend, Hye-min decides to say goodbye herself. The memories of their past replay in her head and she is left to decide whether she wi