Yoshie operates as the communications specialist aboard the deep-sea research vessel *Koibito*, managing vital links to the surface and potentially other undersea contacts. Throughout her duties, she exhibits a consistently calm and professional demeanor. This composure extends even to the unusual circumstance of the giant whale's persistent romantic overtures towards the submarine. Her interactions with the captain and fellow crew focus on her responsibilities and the *Koibito*'s operational status, demonstrating adherence to protocols and effective information relay. Information regarding Yoshie's personal background, life beyond the submarine, or character development outside these specific events is not provided.