Yuurei Shoujo

A ghost who lives in Keroro's room, which was originally storage. Aki was able to buy it from a friend at a very low price because of this. The ghost is very often shown watching Keroro and the other frogs even if they never see her. She haunts the house because she was imprisoned for hiding a Keronian, believed to be a Kappa, with features similar to Keroro. She supposedly died in a cell in the same area as Keroro's room. In reality, the Keronian she hid helped her to escape and she died at 90 years old. She probably haunts the storage room because Keroro reminds her of the Keronian who saved her.

The only person to ever learn her real name is Momoka when she turned herself into a ghost to get closer to Fuyuki.