Yumeha Togashi, youngest sister of Yuuta Togashi, lives with her brother, older sister Kuzuha Togashi, and their mother, with their father also acknowledged as family. She appears throughout the series, starting at age 5 in Season 1, advancing to age 6 in Season 2, and turning 7 during the film "Take On Me." Her physical traits include short brown hair frequently tied in a ponytail, striking green eyes, and a consistent height of 100 cm (approximately 3'3"). Yumeha displays an innocent, playful, and bubbly demeanor. She delights in Yuuta’s past "chūnibyō" alter ego, the "Dark Flame Master," often wielding his prop blade during play. She idolizes Rikka Takanashi for her perceived intelligence and skill, seeking Rikka’s cooking advice to become a good wife someday. Yumeha enthusiastically participates in role-playing games like "house" during interactions. Her character development features notable play sessions with Tōka Takanashi, introducing adult themes like divorce proceedings and child custody arrangements. While Yumeha incorporates these concepts into her games, Yuuta grows concerned about their impact on her childhood innocence. Family dynamics show her engaging in household activities alongside her siblings. Maintaining a steady presence, Yumeha’s core personality remains unchanged, serving as a symbol of childhood innocence shaped by the eccentricities of surrounding adult and teenage characters.