Yume is a reserved yet gentle third-year Information Systems Engineering student, known for her hardworking nature and deep affection for her family. Her innate kindness drives her to help those in trouble without hesitation. While contemplating her future, she frequently compares herself to peers, experiencing anxiety over her perceived lack of distinctive qualities or talents—symbolized in her environment as "rare tags."

This struggle unfolds in a smart city where individuals project identity-representing hashtags onto aerial displays. Yume's personal hashtag fails to "shine" among others, intensifying her self-doubt. Motivated to overcome her insecurities and establish individuality, she pursues a unique personal identifier—a "rare tag" or "weird tag." Outside academic pressures, she finds comfort in baking handmade sweets.