Chiyu Haebaru serves as a marine life caretaker, having lost her prior aquarium position due to difficulties balancing single motherhood with professional demands. This experience fueled her resolve to build a stable aquarium career, leading to a training assignment at Gama Gama Aquarium. There, she clashed intensely with Kukuru Misakino over conflicting methods: Chiyu prioritized formal training and professional standards, while Kukuru favored hands-on experience and personal bonds with the aquarium. Frustrated by Gama Gama's informal practices and Kukuru's rejection of structured protocols, Chiyu deemed the training counterproductive to her goals and transferred elsewhere.

After Gama Gama's closure, Chiyu joined Okinawa’s new Tingarla Aquarium, where Kukuru also worked. Their renewed proximity reignited friction, particularly when Chiyu observed Kukuru circumventing procedures. This tension reflected Chiyu’s rigid rule adherence, born from her past instability and trauma. Her single-mother background resurfaced during this period, explaining her stern demeanor and career-driven focus as efforts to secure stability for herself and her child.

Shared challenges at Tingarla gradually eased their conflict. Chiyu recognized Kukuru’s increasing adaptability and dedication, while Kukuru acknowledged Chiyu’s expertise and underlying motivations. Mutual respect softened their rivalry, shifting them toward collaboration. Chiyu ultimately developed a more balanced outlook, merging professional discipline with empathy for colleagues facing diverse struggles.