Ai Seji (Mio Kudo), who is studying at Eiichi University, meets Kotoha Furuhashi (Maka Osaki), a beautiful woman who was abandoned in a garbage dump. Ai invites the elusive Kotoha to her home, using this as an opportunity to become friends with her, but this proposal is ruthlessly rejected, and Ai learns that Kotoha is a changed name. Instead, Kotoha proposes to be "lovers" until her real name is guessed. Then, in the temporary relationship, if you guess her real name, you will become "friends" as agreed, which is a strange bet. Ai does not retreat and decides to take this bet, clumsily deepening the relationship with Kotoha as a "lover", but the past hidden in her name bares its fangs to the present...