Unbeknownst to him, Aqua's fraternal twin sister, Ruby Hoshino, will be the reincarnation of Sarina Tend?ji, certainly one of Gorou's individuals who was a enthusiast of Ai. Four many years later, Ai is murdered in front of the twins by the same lover who killed Gorou. The lover afterwards commits suicide, but Aqua deduces the murderer could have e