Giko

A ghost that resides in the Satsuki Dormitory. He prefers to reside within 'gaps' - very thin spaces that he is able to squeeze into, such as the space between two pieces of furniture or a crack in a wall. When outside with Yachiko he generally hides himself inside her skirt. He appears to be unable to remain outside of gaps for too long.

In a mission to gain a better understanding of girls, Giko has been working on a "girl dictionary" for many years by observing and sometimes befriending girls and noting their behaviour. According to him, his 'unfinished business' as a ghost is to complete the dictionary, and he will not disappear until this happens.

Prior to meeting Yachiko he took on a more frightening appearance, being drenched in blood. However, at Hitomi's request, he was able to clear the blood away to gain a less intimidating appearance.