A yokai in the form of a high school girl who serves Yamamoto Dury-zaemon, the King of Yokai in the Okinawa Singularity. She is a Kijimuna, a local yokai (Jimotty), and the nickname "Nacchan" is derived from that. Kijimuna (Nacchan) is a character from the event "Chaldea South Sea Decisive Battle! ~I Saw the Shadow of a Mysterious Giant on Majimun Island~". An Okinawan yokai entrusted by Yamamoto Dury-zaemon to act as a guide for Chaldea. She is not a Servant bound to a yokai like Duryodhana, but a pure yokai. Biscione (Caster) also senses something different from her compared to a Servant. She adds "-tya" to the end of names, calling people things like "Mashu-tya" or "Olga-tya." - Personality: She prioritizes "what she wants to do right now" and has a personality that focuses on "enjoying the moment." - Speech Style: Very energetic, speaking with an Okinawan flair. - First person: I (casual/gal style) - Second person: By name - Clothing: Looks like a high school uniform, but she wears it very loosely in a gal-like fashion.

Her nicknames are "Marie" or "Olga," though few call her that in the main story or other works. She is noticeably haughty and hysterical, with high pride, but at her core, she is lonely and a bit of a coward. In a word, she's a wimp. She acts noble and arrogant, but screams when encountering monsters and secretly wants someone to rely on. Perhaps because of this, she is quite dependent on Lev, whom she trusts, both practically and mentally, and is left helpless and flustered when betrayed. She prefers coffee over tea. Also, likely due to past experiences, she harbors a strong inferiority complex, feeling that she is "not recognized." She took over the Director's duties while on the verge of a nervous breakdown, convinced that Mash—the only successful case of Heroic Spirit fusion—would seek revenge on her. On top of that, anomalies occurred, and her lack of Master aptitude was exposed. With bad luck piling up, she is completely cornered at the start of the story. Furthermore, because she was always a step behind, her popularity on-site was almost zero, but she held on as the head of the Animusphere family despite the pressure from those around her. Even the protagonist, who had just met her, described her as "reliable if she stays calm," which Romani agreed with. It's true in a bad way, but she does perform properly in situations where she can actually remain calm. Also, despite being afraid, she does not look away from Mash; she is serious toward the outside world and has a nature that prevents her from doing the wrong thing, no matter how much she dislikes it. - First person: I (formal) - Second person: You / By name

Light purple medium-length bob (sometimes looks pink in certain illustrations) with purple eyes. She wears thin black stainless steel frame glasses, which she removes during combat. A kind girl with a pure and serious personality, though she can be a bit ditzy. She has a heart that considers others. While she may seem quiet at first glance, she also has a curious and active side despite her reserved appearance. While she generally treats everyone with politeness, her lack of communication experience makes her word choices very blunt (sometimes unintentionally spitting venom). She has a serious temperament, but when she gets fired up to be useful to the protagonist, she tends to rush ahead with too much momentum. Specifically, she gets excited in a way appropriate for her age, and when the protagonist takes a role that puts them in the spotlight, she tends to get even more of a boost as a backstage supporter. - First person: I (polite)