Ryouko no Shinrei Jikenbo

Ryouko Midorikawa is a girl in her first year of high school. One day she finds her pet cat Pow drowned in the bathtub. Ryouko knows that he hated water, so she doesn't believe he died by accident. The same night strange things start happening around her. This is the beginning of her strange encounters with spirits, but also the path, which leads to the man she loves.

(Source: Celestial Scans)