Mizuno Souba (蒼波 水乃 Souba Muzino) is the leader of fish clan and lives as mermaid under the sea. She is a mermaid with a brother complex. Mizuno is the Aqua Stranger and stands on 2'o clock. Her birthday is Feb. 1. Her sign is Aquarius. She stole the thunder-stone from Sarai in the beginning of volume 2.
Mizuno is very beatiful and single-mind young woman. She´s only about 16 years old, but already ruling her clan. If somebody does something against her clan or her brother, she gets very angry.She is seen to be stubborn like how she was going to be kill by Ralzone, Sarai tried to save her but she just threw a rock in his face and say she rather be food for Ralzone than be saved by Sarai. But she is seen to be caring like how she almost kill herself because of her selfishness. She only thought she would be the head until her brother came back but then she accept herself as the head.
Sad for her, she´s in love with her own brother: Ginga, who is in the bandit-group of Widoseek. She´s desperate, because her borther wants to stay with Widoseek, she goes to another mermaid: Ralzone, who´s something like a mother to her. Ralzone want´s to help her and gets the thunder-stone from Mizuno, but instead of bringing Ginga back to Mizuno, evil Ralzone makes the ocean disappear. When Mizuno sees her home destroyed, she tries to stop Ralzone and is nearly eaten by her. But Sarai, who was in love with Mizuno, rescues her who she turn down many times. When she´s found by Kyoko, it takes some time until she agrees to go with her as a stranger. While she talkes about how much she loves about her ocean home and agrees to be the true head, her stone accepts her, and she becomes the "Aqua Stranger". She fell in love with Sarai in volume 3.