Kodai Shoujo Dogu-chan

By chance, a hikikomori named Makoto Sugihara finds a strange breastplate buried in the woods. When he places his palm on the breast plate, its design gets burned into his palm and awakens a girl named Dogu-chan, a hyperactive yōkai hunter from the Jōmon period. Because he had touched her breastplate, Makoto is now bound to Dogu-chan as she adapts to modern day life, forcing Makoto to go with her as she fights yōkai in magic armour with her dogū assistant Dokigoro while slowly prying Makoto out of his shell, whether he likes it or not.