Kanojo o Dere Saseru Houhou o, Shourai Kekkon Suru Ore dake ga Shitteiru

Q: Why did you choose this high school? A: Because my future wife is enrolling here. When I woke up, I had time-leaped 15 years into the past. Standing before me was Yuki, my future wife, wearing a school uniform I don't recognize. In the original timeline, we wouldn't meet until we became adults and eventually got married, so we're still strangers for now. But I know that she distrusts people, has no friends, and spends her school days alone. I also know she'll deeply regret that time in the future. So this time, I'm going to rewrite her youth. "How do you know my secret!?" "Because we're husband and wife... in the future."