|Other names||Wakasa-san (by Tatsumi)|
Fish-san (by Kasumi)
|Age||20 (according to him)|
|Physical and Vital Statistics|
|Heigt||1,86 cm (6'3)|
Wakasa is a handsome merman with very long, silky, blonde hair, which edges up at the back of his head (similar to a ponytail) like the back fin of a shark which then allows the rest of his hair to fall freely beneath. His eyes and fin are both colored in a blue shade, while his skin is really smooth and slippery.
In Chapter 97, he is revealed to have a different form wherein his pupils are slit and scales frame his face, neck, and shoulders and arts of his arms. His ears also become fin-like. Wakasa is able to control water in this form.
Wasaka is carefree and not shy about letting himself be spoiled by Tatsumi's kindness. He does not know much about human society and is very impressionable. He is very huggy and doesn't mind pulling Tatsumi into the tub to bathe with him, or hugging onto him whenever he's sitting too close to the tub for too long. Wakasa also loves eating hamburgers and when Tatsumi mentioned a possibility of switching from hamburger meat to tofu to save on expenses, he was devastated.
Wakasa originally lived in a heavily polluted river by the upstream dam. As it became too troublesome to live in that area, since rumors about mermaid sighting had started to go around, he decided he had to leave and was found stranded by Tatsumi, who invited him to live in his comfortable and clean bathroom.
Wasaka meet Echizen and Takasu when the two were young and started to play together. However, Takasu and Echizen's friendship ended after they began to fight over Wakasa. Wakasa, however was oblivious to this conflict. Not much more is known about his past; in chapter 68, Echizen said that humans "did bad things to him in the past".
It is later revealed that Wasaka first meet Tatsumi when he was around ten, after he fell in a river while he was fishing and Wakasa rescued him. However, after being offended by Tatsumi, he threatened him so he will not tell anyone about his existence. This made Tatsumi to hate the water, taking baths and mainly, the slime. When they met again years later, neither of the two seemed to remember each other.
Unbeknownst to even himself, he has unspecified powers that include levitation and Hydrokinesis. He retains no memories after activation. During this event, his pupils become slitted and he gains scales on his face.
Wakasa doesn't like to say his true age and instead he lies saying that he is 20-years-old. However, it's hinted that he is actually over 200 hundred years old, as he was alive during the Black Ships, and the 1928 Amsterdam Olympics.
- Wakasa is afraid of birds, although he does not mind them if they are toys. He also used to be afraid of cats.
- He hates the color green, as the river he lived in had a green color due to the amount of weeds, dirt and plastic bags inside of it.
- He hates vegetables.
- He can survive out of water for a short time provided he stays wet, but if he dries out he could die.
- On land, he can move about by crawling, though he rarely ventures far from the tub.
- He is a Pisces (according to Kasumi since he doesn't remember his birthday).
- His name may refer to a type of fish known as wakasagi.
- The author has mentioned that his name is a reference to a land in the "Yao Bikuni," a japanese folktale featuring early ideas of mermaids called "Ningyo."
- Like sirens in mythology, he has a beautiful singing voice and has accidentally caused several middle aged women to fall under his spell while singing "Drowning Lessons" by My Chemical Romance.
- He knows many music artists such as Beethoven, Bon Jovi, and My Chemical Romance.
- His hair curls up in humidity.
- His butt is bio-luminescent.
- He enjoys alcohol too much.
- He has great eyesight.
- He has dressed up as characters from both Sailor Moon and Dragonball Z.
- He likes to imitate the painting "The Birth of Venus".
- He likes bubble baths.
- His teeth are sensitive to the cold.
- During his mating season, which is once per century, his tail turns red and he gets horny.
- The furthest he's gone with someone is holding hands.