Yui is a cool-headed girl who often acts as the voice of reason to the other characters. She is a mature, reliable and no-nonsense person. Although generally quiet, she will often times burst into laughter upon hearing Ayano's puns or Kyoko. She is also renowned for her retorts, especially directed to Kyoko. She is a reliable friend and lives alone in an apartment complex although she won't admit it. She seems to be the one most respectful towards Akari among the Amusement Club members.