Mitsuru Hattori
Mitsuru Hattori (はっとりみつる) is a Japanese manga author whose works include Inu Neko Jump! (イヌっネコっジャプ!) (2003-2004) about track and field sports, Otogi no Machi no Rena (2004-2005), Concerto, and Kenkō Zenrakei Suieibu Umishō (ケンコー全裸系水泳部 ウミショー) (2005-) about a school swimming team with a mermaid. The stories are typically risqué (a.k.a ecchi) romantic comedies.
There is a Japanese Wikipedia page with further information about this author: http://ja.wikipedia.org/wiki/はっとりみつる