
Visually Hangyodon is a fish, but the kanji for his name is spelled out to read "Half-Fish Man", which fits in with the more adult personality his character is given in fiction.
In most of his animated films, Hangyodons' occupation is as a Detective, but in the 1993 OVA "SAM TO CHIP NO WA HACHAMECHA DAI RACE" (Sam and Chip's Great Messy Race), he stars as a racer.Hangyodon has had two main love interests over the years; Kingyochan in animation, and a human girl named Kumiko in his comic series that ran in Ichigo Shimbun. He had two comic series in いちご新聞; "Hangyodon" and "Hangyodon's Lecture of Manners".
In his comics, Hangyodon has a family, but his parents and older brother were never officially named. This was confirmed by creator Hisato Inoue on his twitter. Hangyodon's sister, however, is named but is no longer used (or seemingly recognized/claimed by Sanrio at all). Her name is Sumire-chan(すみれ), and she is a half person, half salamander. Sumire debuted the year after Hangyodon and has a competitive personality, and tends to be more harsh than she intends.

They are a boy group created by Sanrio with the goal of uplifting and spreading happiness to the world through kawaii by singing, dancing, skits and adventures! The main message their group spreads is "大丈夫! 君は君のままで、きっとうまくいく." (It's okay! You're still you, I'm sure it will work out)
They have collaborated with Pocky, Joypolis, JR Shinkansen and even had their own cafe pop up!