Darashinai Onee-san wo Kaitai

One day, Haruto-kun, a junior high school boy who loves to help others, encounters a half-naked lady on the street! Her room is a mess, she can't put on her clothes properly, and when she gets drunk, he can't help but want to help her. He unintentionally ends up taking care of her...? Do you like a slutty sister who is unaware of her sexuality and is even cuter?