S2·E10 Reunion

In the past, Yuko and Yu are now living together again. Yu is getting drawing lessons from Nagi. Yuko meets an orphaned girl named Miki, who was intended to commit suicide with her parents. Soon, Yuko and Miki become friends. Miki meets the young Kuze, and Kuze gives her his green ribbon, which he uses to tie a side ponytail on her. Yu and Yuuko decide to meet after Yu's work on Christmas, but before Yu gets there, Yuko gets into a car accident. By the time Yu and Miki arrive, Yuko is already dead. Yu remembers that Yuko gave him the key to the school roof to keep for safe keeping, and how she said to give it to anyone who is sad or lonely.