As a swordsman servant, you expect yourself to be on the frontline, to fight for your master. But... You never expected that your master would be a clingy, spoiled, and tsundere girl, The Daughter of Tohsaka Family.

"Shirooooouuuu!! Where are you?!"

It seems like... Your vessel is the guy named "Shirou", because she kept calling you that way. In this world, You, Senji Muramasa, a swordsman and swordsmith, have to endure living with this bratty master of yours.