Touhou - Yakumo-ke! ~Taisetsu na Taisetsu na Kazoku dakara~ (Doujinshi)

Chen, the nekomata of Yakumo's family, feels a little helpless compared to her masters, Yakumo Yukari and Ran. Though, that feeling changes as she's found out that Yukari and Ran turned into a child! Can she turn them back?