|Tongo Mizushima and Ria Mizushima|
|Family||Gengo Mizushima[Father(most likely)]|
Crea Mizushima (eldest daughter)
Mirea Mizushima (youngest daughter)
|Power(s)||Possibly high intelligence due to being part of the S Project.|
|Occupation||Founders of the S Project|
|Affiliation||The S Project|
Mr. and Mrs. Mizushima were the parents of Mirea and Crea Mizushima, with their father Tongo most likely the son of Gengo Mizushima, (since they share the same last name). They were also two of the core members or founders of the original project that created Shiningman.
Tongo was a tall man with short-cropped black hair and a small goatee beard. Their daughters take their appearance after their mother, who was beautiful blonde woman, said to be from England, which makes both girls half-English. Her real name has not been stated.
Not much is known about them except they were very loving. Crea and Mirea both have fond memories of them.
Mizushima's past is unknown, but more than seven years before the start of the series, he and his wife, along with Shouichirou Kizaki and another person, took part in creating Project Shiningman or the S Project, which was intended to bring hope to a violent and crime-ridden world. It wasn't meant to be a very large endeavor. However, the initial success of Shiningman would eventually cause the experiment to reach heights that no one could predict. With Tongo's father Gengo later added onto the team, along with Dr. Teramishi and others, they created a true superhero, who was entirely embraced by the people of Japan, thereby causing what was later known to be Hero Fever.
However, the success of the project did not last. Tongo later discovered that Teramishi was performing illegal and immoral bio-experiments for profit and fired him. Then came a yet-unexplained event in which Tongo and his wife were killed, along with Shouichirou's wife. Due to this event, Shiningman also disappeared from the public view, while Gengo withdrew from the project to look after Tongo's orphaned daughters, Crea and Mirea. It is heavily hinted that Tongo and his wife were actually murdered and that Shouichiriou may be either the killer or was deeply involved in the killings.