The Hashira

The story Kyojuro Rengoku deserved is being served you're welcome.

Second book to The second Sun breather.
Kyojuro survived the Mugen Train. That was only the beginning.

Now engaged to Yoko Tsugikuni, he should finally have the future he nearly died for. Instead, the Demon Slayer Corps demands an heir from the last Sun Breather, a mission forces Kyojuro to kill a human, and an Upper Moon begins hunting through villages hidden beneath endless winter fog.

With hundreds of lives under his command, Kyojuro becomes everything a Hashira should be-powerful, brilliant and impossible to break.

But Yoko is beginning to realize the truth:

Yoko realizes, that duty, may be the end of love.