Yoiko

Yoiko (よいこ) is a seinen manga written and illustrated by Yūgo Ishikawa and serialized in Big Comic Spirits. A 20-episode anime series by Studio Pierrot was produced.

Plot
Her name is Esumi Fuuka. Standing tall at 163 cm with a slender bodyline, she must be a university undergraduate; however, in reality, she is only an elementary school student. With a body figure of an adult and the mentality of a small child, she creates many misunderstandings around her.