Yagyū Suō

is the main hero of the series and a cursed humanoid weapon. He is from the Yagyū bloodline, whereat he has higher concentration, speed, strength, and other given abilities. He has romantic feelings for Ame.

Suou has romantic feelings for Ame and her last words to him were "I'm sorry. I'm sorry. Thank you for everything. Suou, I love you." then he wakes up and returns to earth.