My Stepmom's Daughter Is My Ex

継母の連れ子が元カノだった

Mizuto Irido and Yume Ayai dated in middle school and broke up the moment they graduated, expecting never to see each other again. Two weeks later their parents announce they're getting married, turning the exes into stepsiblings under one roof. Both agree to a strict rule: whoever admits lingering feelings first loses. But old habits and forced proximity keep testing that resolve. This manga adapts the ongoing light novel series.