つづら先輩は元カノだから

Synopsis

A romantic comedy about ex-girlfriend × ex-boyfriend getting back together! Osanai Ritsu is a high school boy who wishes for nothing more than a perfect, peaceful life. But at the high school he attends is Tsuzura Sana—his Senpai and the "ex-girlfriend" he dated back in middle school...?! His high school life, constantly thrown into disarray by his unpredictable ex-girlfriend, is about to begin...! If you had an ex-girlfriend like this, she'd drive you crazy...!!