She is a bad student and a troublemaker compared to her more straight-laced sister. She's more emotionally mature than the easily upset Komari, but is childishly irresponsible and often acts lazy. She often pesters her older sister and sometimes treats her like a child; however, deep down she still respects her older sister.
Like Miyauchi Renge, she sometimes calls Komari "Koma-chan"; however, this is generally intended as pestering. Normally she simply calls Komari "onee-chan".
In season one it's revealed that she used to have a childhood crush on her older brother Koshigaya Suguru.
