Momoiro Youkai Story ~ Nako's Lusty Journey

One morning Nako notices that the boy next door, to whom she was like an older sister, is very upset about something.
When she manages to get him to talk, Nako learns that the boy is missing something much needed.
So, Nako sets out in pursuit of the stolen item, meeting many yokai and other victims of similar shenanigans along the way.