When he was a kid, Yukiteru lit candles and stared at the candlelights, but the candles fell down. A fire broke out and the whole house burned into ashes. Since that time, he has lived at the home of childhood friend Yuno. Yukiteru and Yuno are a couple known to everybody. Rena is a new transfer student in Yuno's class. She becomes interested in Yukiteru and one day they have an intimate encounter. This changes Yukiteru and his relationship with Yuno.
