Prince of Tennis: Mu Ran's Beautiful Years

The thing Yukimura Seiichi regretted most was agreeing without hesitation when Kazama Muchan asked to break up. That would have been bad enough, but only after they split did he realize his heart had long since fallen into her hands.

And so...

“Muchan, they say a good horse never turns back to eat old grass, but you’re not a horse, and I’m not grass. So take me back, will you?”

Kazama Muchan: “...”

“Muchan, everyone says I’m too scheming, but look, it’s all white in here. They must be blind, right?” Yukimura Seiichi said, then took Kazama Muchan’s hand and smiled with utter delight.

Kazama Muchan: “...” Someone please take this scheming man away!

Once Yukimura Seiichi understood his own feelings, he lived by just two principles: tennis was his faith, and Kazama Muchan was his. No one else was allowed to take her from him.