Ichiko is in fact a ghost. Her story begins 22 years ago: a previous Elder actually Mizuhos mother had a close relationship with an underclassmen who had a weak body. When that underclassman heard that the elder was graduating and getting married the same time she had to see her before she left. The underclassman went to the Elders room and waited but she died before she had the chance to talk with the Elder. That room has been deemed the quotclosed roomquot ever since until Mizuho arrived and started living it according to his grandfathers will. She is very energetic and hyperactive often talking very fast. She took some time to understand that she is a ghost and by that dead. She says that Mizuho looks very much like her previous Elder love interest.