Atui is the daughter of Soyankekur, one of Yamato's Eight Pillar Generals, and holds the position of princess in Shyahoro. She shirks her royal responsibilities, frequently running away to pursue her personal quest for an ideal romantic partner, leading to countless failed romantic pursuits. She possesses short black hair with ornaments at the ends, orange eyes, bat-like ears, and a small tail. She dons an orange-and-white leotard with metal accents and matching boots. A distinctive feature is the Fururuetrun, a light-blue cap that is actually her alien jellyfish companion Kurarin, which she wears on her head. Her personality exhibits a stark duality. Daily life reveals a playful, lighthearted demeanor focused on romance and bonding with friends; she enjoys social activities like drinking with companions and shopping with fellow princesses such as Rulutieh, but harbors a strong aversion to insects. Conversely, in combat, she transforms into a renowned berserker who revels in bloodshed. This battle lust is an intrinsic part of her nature, driving her to seek conflict, portrayed less intensely in anime than in source material like visual novels and games. Her story begins when fleeing her duties leads her to encounter Haku in Yamato. She forces him to act as her guide to romantic locations, becoming visibly flustered around him during their outings. Their relationship deepens through late-night conversations and shared secrets over drinks, culminating in her developing romantic feelings for Haku. She affectionately calls him "Onii-san," acknowledging him as someone special. She forms close friendships with Kuon and Rulutieh. With Kuon, she bonds over their shared status as displaced princesses, developing a competitive urge to challenge her upon recognizing Kuon's hidden strength. With Rulutieh, she shares an interest in romantic tales and shopping. Her relationship with her father, Soyankekur, is marked by his overprotectiveness, especially regarding Haku. Despite this, she maintains independence, often residing at the Hakurokoku Inn in the capital. Her development includes moments of vulnerability, such as seeking solace in drink after romantic rejections, comforted by Haku. Her journey reflects a gradual acknowledgment of her own emotions, particularly her love for Haku, while balancing her dual identities as a romantic seeker and a warrior.