[Decimus]

椛
もみじ

Rare kanji, can also be written as 「紅葉」. Means "autumn (leaf) colours". Technically, it also refers to the Japanese maple (Acer japonicum), but 「紅葉」 can be used to describe other maple trees (Acer sp.) with exceptionally beautiful foliage.

*cough* Picked it up in a certain danmaku game. *cough*