Kokoro has no time to ponder her professional purgatory when she finds herself the mentor to a taciturn girl named Hikari Inoue bearing a Librarian Association commission as a special-case librarian just like herself. While Iina and Aruto speculate on Hikari's perspective of her new surroundings, Kokoro takes it upon herself to warmly welcome her protege with some brewed tea; even with a custom-designed librarian uniform demonstrating Iina's goodwill, Hikari is too wracked with anxiety over her mom's medical status to acknowledge that labor is expected of her at Kokoro Library. Considering the significant headway she makes with the daily chores at the Library and even accommodating Akaha borrowing a book under Kokoro's tutelage, it seems that Hikari just needs somebody to pay attention to her and spend time with her. While watering the flowers, Kokoro's notice of a photograph of Hikari's mother prompts a »Hands off the photo, sister!!!« repulsion from the fleeing Hikari; a nocturnal foot race later, Hikari's confession about wanting to see her mother leads to Hikari finding a kindred spirit in Kokoro who was never given the choice to meet her mother.