Isuzu works as a miko at the Uramimi temple and has been helping Haira out since she was eight years old. She's gained some recognition as a blogger, which has earned her admirers like Koito.
She gives Haira a hard time about her gambling habit—and honestly, she's not wrong to worry—but it's clear she cares about her deeply. As a quirky hobby, Isuzu makes collectible cards featuring photos of Haira, which says something about how much she's invested in their relationship.
Content compiled by AnimeList.moe from publicly available sources.