Title: Mujaki no Rakuen
Synonyms: Paradise of Innocence
Aired: Aug 29, 2014 to August 29, 2016
Shouta, a 25-year-old NEET, is mocked by his former female classmates who’ve all become successes, at their class reunion. A mysterious incident at the school pool throws him back in time and lets him deal with those same classmates back when they were fifth grade girls.