Shikimori is Izumi's girlfriend and the female protagonist of the Shikimori's Not Just a Cutie manga series. Described as being very cute in both personality and appearance, Shikimori is considered popular and is loved by those around her, such as her best friends Hachimitsu and Nekozaki.

Despite her inherent popularity, however, Shikimori often opts to spend time with Izumi over most others, and is shown to deeply love him as her boyfriend. What he loves most about her happens not to be her cute side though, as Izumi instead likes the "cool" side of Shikimori—and her ability to switch to it almost instantaneously!