Эп. 7: По мере приближения зимы Рака замечает чёрные пятна на своих крыльях, а Кку остаётся отсутствующим.

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Rakka refuses to believe Kuu will never return from her Day of Flight, since it has now been a month since then as winter soon approaches. She goes insides Kuu's room to clean up the place, but she begins to notice sickly black spots begin to appear on her own wings. Depressed, she goes into town alone to get something to eat and later encounters Hyoko. Although he is relieved that Reki was not the one who has disappeared, Rakka becomes upset since she really cares about Kuu. When Rakka returns to Old Home later that day, more black spots start to show, and Reki begins to worry when she catches sight of this. Rakka cries as she runs back to Kuu's room, and Reki follows and embraces her. Reki gives Rakka special medicine extracted from an elderly tree for her wings. Reki explains that a Haibane is deemed to be sin-bound if they have forgotten their dream while inside their cocoon, and, unlike blessed Haibane, will never have their Day of Flight. She also reveals that she was sin-bound when she was a newborn and that she had been haunted by nightmares since then, trying to remember her dream. (Source: Wikipedia)