The main female protagonist. Tsumiki is somewhat petite and dainty in stature. She has a tsundere attitude: She is sharp and sarcastic on the outside and loving on the inside. She is hopelessly in love with Io. Every time Io gives Tsumiki a pat on the head or Tsumiki sees something she likes, she grows cat ears. Tsumiki is unusually strong for her size, and this is often shown at Mayoi's expense. She is skilled at arcade games and is very similar to Konata Izumi, from Lucky Star.