Hammer Session (Japanese: ハンマーセッション!, Hepburn: Hanmā Sesshon!) is a Japanese manga series written by Yamato Koganemaru (first 31 chapters) and Hiroyuki Yatsu (onwards) and illustrated by Namoshiro Tanahashi. It was serialized in Kodansha's shōnen manga magazine Weekly Shōnen Magazine from November 2006 to December 2008, with its chapters collected in 11 tankōbon volumes. A second series, Hammer Session! In High School, was serialized in the same magazine from May to November 2010, with its chapters collected in three volumes. An 11-episode television drama adaptation was broadcast from July to September 2010.