Yuuna Matsumoto

Yuuna is the cheerful little sister of Matsumoto Koko, a bright-eyed elementary schooler whose innocent charm stands in delightful contrast to her quirky, obsession-driven sibling. Where Koko fixates intensely on Hoshino Miya, Yuuna simply radiates warmth and childlike joy toward everyone around her. She serves as a heartwarming presence throughout the story, offering moments of light relief and genuine sweetness. Adding to her endearing nature, she owns a puppy named 'Miya'—sharing the same name as the main character—making her a fan-favorite supporting role.