S1·E22 He Kept It...

Rin Kamishiro is still worrying about what will happen to Kazuki if she returns his ashes, things are made more complicated when Kuriko decides that Kazuki will take Rin on a date for the day in an attempt to restore Kazuki's ashes. Fearful that once his ashes return, Kazuki will lose all memory of the girls; Rin resolves to leave, with Kazuki's ashes and never return, but she repents after witnessing the lengths he will go to keep a promise. After demanding that Kazuki will not forget the girls, she returns his ashes and everything seems fine until Kazuki collapses in pain. The episode ends with Yamase on a train wondering how everyone is.