Nakamura-san, the Uninvited Gyaru Vol. 4

It's been six months since brash gyaru Nakamura invited herself into the apartment--and life--of timid otaku Akiyama. Things get even more exciting when after a tiring day of hunting for aliens, Akiyama finds himself with an unexpected surprise--sharing a hot bath with a naked Nakamura! Cohabitation is never easy when polar opposites are involved, but it gets even harder when Nakamura's mom shows up! How will Akiyama explain himself now?