Unbeknownst to him, Aqua's fraternal twin sister, Ruby Hoshino, would be the reincarnation of Sarina Tend?ji, among Gorou's people who was a lover of Ai. 4 yrs later, Ai is murdered before the twins by precisely the same lover who killed Gorou. The enthusiast later commits suicide, but Aqua deduces the murderer could possibly have had his and Ruby'