Sumiko-San's Ironclad Defense! ~The Gyaru Senpai Offering Me Romance Advice Is Just Too Overpowering~

Drifting apart from his childhood friend, rejected by the class representative, and looked down upon even by the girl he thought was a fellow otaku—just when life couldn't get any bleaker, Sumiko-senpai appears before him. Flashy in appearance yet infamous for having an impenetrable guard, she is the legendary "Ironclad Gyaru"! "Hey, don't you think your defense is way too soft?" The secret technique behind her dating mastery turns out to be... the "Ten Doctrines" of Mozi, the ancient Chinese philosopher?! With every piece of unexpectedly profound romance guidance this strategist gyaru dishes out, his youth begins spinning out of control.