In 2003, he began Yotsuba&!, a slice-of-life manga series about the adventures of a five-year-old girl; it is serialized in the monthly magazine Dengeki Daioh.
About a year after entering the university, he began doujin activities in a private magazine called "A-Zone," drawing fan-made parody manga of Sailor Moon and other characters.
were both selected as one of Japan's Top 100 Media Arts in the manga category.
In May 2000, he established Yotsuba Studio in Nerima-ku, Tokyo, with Hideki Satomi.
Although he does not disclose much about his private life, in a blog post written in 2011, he has stated that he feels hesitant when buying children’s furniture to use as reference for his manga because he has no children.