Mizuhiro Mikado (birth name Hydron [ハイドロン (haidoron)], made known in the Grammaton as either Mizuhiro Mikado or Hydron Celeste [ハイドロン セレスタ (haidoron seresuta)]) is the alias of Grammaton's Xth Member. He is currently suffering from amnesia and satisfies his lack of memories by killing anyone that calls him an effete or insults his mannerisms.