Kaishaku (介錯) is a group of two manga artists consisting of Hitoshi Ota and Terumasa Shichinohe. The name comes from Kaishakunin (介錯人), an appointed second person whose duty it is to decapitate one who commits seppuku - ritual suicide by disembowelment. Their anime also tends to have a happier ending after the credits on each last episode. Source: Wikipedia (en)