Haibane Renmei - Season 1 Episode 6 End of Summer / Rain / Loss
Overview: With winter approaching, Kuu gives Rakka a coat and helps her choose a room to live in. Kuu thanks her for the influence she has been, and Rakka notices that Kuu's halo is flickering. The other Haibane tell Rakka about Kuu's history of trying to imitate her older companions. As night falls, it starts to rain, and Kuu is nowhere to be found.