Made in Abyss Movie 2: Hourou Suru Tasogare

After leaving Ozen's Seeker Camp, Riko and Reg descend into deeper layers of the Abyss, where the creatures grow deadlier and the Curse of the Abyss becomes more severe whenever they try to ascend. In the Fourth Layer, Riko suffers an almost fatal injury and Reg discovers he cannot save her alone.

Nanachi appears and treats Riko, then reveals to Reg a painful history shared with a companion named Mitty and the reason for knowing so much about the Curse. Nanachi's next request is as painful as it is necessary and changes their journey permanently. Once Riko recovers, the group continues downward toward Ido Front, where someone connected to Nanachi's past and one of the Abyss's darkest secrets is waiting.