I Want to Connect, but I Can't - S1.E10

Kazuki, Enta, and Keppi encounter Dark Keppi, the corporeal form of half of Keppi's shirikodama held by the Otter Empire. Otter, having learned of Reo's plan to use the dishes on Mabu, transforms Mabu into a zombie. Keppi transforms Reo into a kappa, who recovers Mabu's shirikodama and learns that Otter forced Mabu into giving up his connection with Reo in order to live. Mabu tells Reo that he loves him, causing his mechanical heart to explode. A grieving Reo attacks Kazuki, Enta, and Keppi, but is shot and killed by Toi, who wishes to use the dishes to bring Chikai back to life. Kazuki uses the dishes to save Enta's life, and Toi is absorbed by Dark Keppi.