グループ・タック
is a Japanese manga series written and illustrated by Satoru Ozawa and serialized in "Weekly Shōnen Sunday" between 1963 and 1965. The manga series was adapted into two original video animations (OVA). The first OVA, titled , was produced by Knack Productions and released on January 10, 1997. The second OVA, titled , consisted of two episodes produced by Group TAC and was released between September 26, 2003 and April 28, 2004.