Yuu Koutari

Height: 150 cm

Black★Rock Shooter (OVA)
Yuu has choppy tawny hair and hazel eyes. She is also very short in stature, much more so than Mato or Yomi. She wears the same school uniform as the former and latter.
Yuu is excitable and perky; however, she is shown to have a dark side. She is also very possessive of Mato, and has an awkward time whenever she is hanging out with Yomi.

Black★Rock Shooter (Anime)
Yuu's hair is more combed down, and not as choppy as it was in the anime. She also now wears an orange hairclip on her left side, and wears a school uniform different from her OVA appearance.
Similar to her OVA incarnation, she is excitable and perky; she is also eager to tease Mato often. Unlike her OVA incarnation, however, she is perfectly comfortable with the idea of Mato having other friends, and in fact actively teases Mato about her friendship with "her Tiny Bird".

She is fond of skipping classes in favor of drinking coffee at the consultation room. Mato notes that she is trying to be mature for some reason, and indeed she takes concern over Mato's well-being. Mato also says that when she knew her in kindergarten, she was excessively more hyper, and often did "weird things". However, this personality is of Strength, who was in Yuu's body in the real world.