I am Japanese.
Thank you for being fond of Japanese pop culture.
The avatar you want is called Japanese Unreal (Magical Girl、魔法少女”Mahoh shohjyo”).This Japanese culture is thought to have been invented by Japanese manga artist Fujio Akatsuka and others with reference to the American magic comedy drama.Now with the addition of battle elements, it is also popular in Japan.
Unfortunately, I could not become a mainstream in SecondLife.
I will introduce it to the extent that I know.
Japanese Unreal Avatar
Second Street Tokyo
Wonder Japanese Village