Myuu (or Mew), in part because her aura power deals with fire, is afraid of the rain to the point she will miss days of school when it is raining and possibly suffer panic attacks if forced to be out in the rain. She is distant, even to the point of slight rudeness, because of a traumatic experience in her past: during her childhood, her mother was killed during an Aura experiment. The explosion caused the lab sprinklers to go off, showering her shocked self with water; this caused her dislike for rain.
With her friendship with Orina and Ai she slowly begins to warm up. Myu shares a bond from childhood with Ai, though neither of them realize this bond at first