Mikaru Amagi

She's a rich, yet desperately lonely girl who has lost all hope; she falls in love with Kaito to the point that, in Lucia's perspective, he has forgotten his mermaid love completely, and is desperate that he return her feelings. Mikaru also seems to be a sickly girl, collapsing to the floor every time Mikeru appears somewhere else or when Kaito is near Lucia (in order to keep Kaito to herself).