mikawa kai

Kai is the wealthiest teenager in Japan, being the fourteen-year-old heir to the multi-million dollar Mikawa Corporation. He competes with Nagasumi for Sun's affection and potential marriage. Originating from a different mermaid clan, Kai transforms into a full killer whale when exposed to water, unlike Sun and Lunar who take on a human-torso-and-fish-tail form under similar conditions. Interestingly, Kai suffers from agoraphobia, compelling him to travel exclusively via submarines and don an astronaut suit while in open spaces. During his search for a servant, he forms a friendship with Saru. His name bears a connection to Mikawa Bay and Neptune (海王星, kaiōsei?).