Yuuna Matsumoto

The younger sister of Kouko Matsumoto, this character makes her debut during a shopping excursion taken by Miyako and Hinata Hoshino. Though her appearances are brief, she establishes an important familial connection within the series' social circle. Her introduction occurs naturally as the Hoshino sisters venture out into the world, providing a glimpse into the domestic life and sibling dynamics surrounding the main cast during their everyday adventures.