Reika Yamamoto is the main character in Bleach: The Chronicles of Reika , Bleach: The Death Seal , Bleach: The Final Act and Bleach: The New Family .She is a 3rd Seat Shinigami of 10 Division and is Captain Toshiro Hitsugaya`s lover and the mother of Shirayuki and Koyuki Hitsugaya. She is also the older twin sister to Mizu and the younger half - sister to the deceased Ume and Rukio Koyoshi. She is the next in line of the Yamamoto Clan and the Koyoshi Clan in the Soul Society. == ==== ====