Kiyohiko Azuma (あずまきよひこ, Azuma Kiyohiko, born May 27, 1968) is a Japanese manga artist. From 1999 to 2002, he authored the yonkoma comedy manga series Azumanga Daioh, which was later adapted as an anime series by J.C.Staff. 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.
Kiyohiko Azuma's Yotsuba website(in Japanese)
Kiyohiko Azuma at Anime News Network's encyclopedia