Subject 594

Kayamari Shimitsu (カヤマリシミズ Kayamarishizu) is a very loosely referenced character throughout the Riaritī series. The title of the second game, Riaritī Ju - Error 594, is a reference to her character. Though most misunderstand the title and her existence, she is very important. However, much like Michi no Toki, she makes very subtle appearance, and there is usually difficult steps to follow in order to achieve the opportunity to catch a glimpse at her character.

Unlike Michi, however, she is not introduced in the main anime or manga, and instead makes a guest appearance in a xfanimation posted on YouTube by user 594. This user cannot currently be found due to the amount of accounts with "594" in their name.