Toshio's girlfriend Yui visits Toshio's house. Toshio's brother Hikaru meets Yui and finds out that she is a de M. Hikaru, who planned to train Yui, stares at Yui and treats her gently. One day, while Toshio is away, Yui comes to the house to pick up something she left behind, and takes tea from Hikaru, spilling it between Hikaru's crotches.
