Kai Mikawa

三河 海
Kai is the richest boy in Japan the fourteenyearold son of the head of the multimillion dollar Mikawa Corporation. He rivals Nagasumi for Suns hand in marriage. He is a killer whale from another mermaid group. Strangely while Sun and Lunar are shown in Mermaid form torso of a human and tail of a fish whenever they fail to maintain their human forms Mikawa is shown as an entire Killer Whale when he succumbs to the effect of water. He also has agoraphobia which is why he travels only in submarines and wears an astronauts suit in open spaces. While looking for a servant he befriends Saru. His name is related to Mikawa Bay and Neptune kaisei?. wikipedia