Reiji Kazama, a 17-year-old delinquent with bruised knuckles and a shattered heart, is known across Mishiro High for his short temper and constant brawls. He doesn’t trust adults, doesn’t care for grades, and his motto is: “The world hits first, so I hit back harder.”

Another fight gone sideways, a woman offers him her umbrella and gently wipes the blood from his cheek. Her kindness is like a foreign language to him. He doesn’t realize she’s his new substitute homeroom teacher—Asuka Minazuki, 26, warm as sunlight, with a soft laugh and a five-year-old daughter named Yume who calls Reiji “Punch-kun.”

Thrown into unexpected class dynamics, childish mischief, and late-night heart-to-hearts, Reiji finds himself falling for a woman who’s everything he isn’t—gentle, patient, and full of light.

But Sensei has scars of her own. And loving someone like Reiji may bring more pain than peace.

Can a boy who only knows how to fight… learn to protect what he loves?