Mononofu!

The time is the Warring States period. Born in the wilderness from corpses after a battle, a lonely vengeful spirit is inexplicably compelled to follow a masculine general who is passing by. The vengeful spirit is overflowing with nothing but sorrow and malice, and that night, it appears before the general to curse him to death. However, the benevolence of the general who embraces it pierces its heart, and it wishes to live at his side instead...?! (Source: Gentosha Comics, translated)