Go Nyandaber Z - S1.E9

There is a Girls' Dolls Festival and Cha Cha wanted to celebrate, but since Seravi forgets it since he is a boy he gives her an ancient fighter doll instead of a girl's doll when Cha Cha asks for a doll. When she finds out from Shiine, Riiya, and Doroty that the doll is not a girl's doll she gets upset and runs away. Shiine and Riiya follows her. Then the trio meets a genius inventor Mikaneko and his infamous Nyandabar Z.