YYH Official Characters Book: Togashi’s comments about Itsuki, Dr. Kamiya, Mitarai, Hagiri, Amanuma and Makihara.
Itsuki - “Gate Keeper”: has the ability to open a dimensional door. He is a lower B-class youkai called "Yaminade", but can move into the subspace in an event of emergency in addition to have a quite high defense. After being almost defeated by Sensui, they started *dating. It seems he was going out with other humans before meeting Sensui.
*T/N: the verb “tsukiai” (つきあい) is generally used when you’re going out on a date with someone, but the meaning can change according to the context. For example: “to accompany somebody” without any romantic involvement. But, as we don’t have enough context here, I think the author wanted to leave their relationship open to interpretation.
Minoru Kamiya - “Doctor”: can make humans sick within his territory’s area using a virus created with "nen”. He also has a knifehand strike (tegatana) like a sharp scalpel. He’s an excellent surgeon but has no professional ethics. He is always dreaming of cutting people up. He was involved in an injury case that occurred during his school days, but it was handled confidentially by his father’s power, the hospital director. He still has a complex about this incident and wants to kill his father one day.
Kiyoshi Mitarai - “Seaman”: can mix his own blood with liquid to create a liquid organism. Once captured, you cannot escape unless you defeat him. He’s once drowned in water, he is good at swimming but has a fear of water somewhere in his mind. He recently stopped the swimming school after attending for five years. But the reason wasn’t the fear of water, he was disgusted with himself who sexually looked at women in swimsuits.
Kaname Hagiri - “Sniper”: has the ability to use his energy to manifest targets on an opponents' body and to imprint his energy into projectiles that will never miss the targets. At the age of 16, he was attending a private high school. His father was a police officer but died in service two years ago. Contrary to his public face of an exemplary policeman, Hagiri feared and looked down on his father who was a vicious drinker at home. His future dream is to be a lawyer or a criminal.
Tsukihito Amanuma - “Game Master”: can bring video games to life and make the opponent a character in the game. He’s an only child whose parents both work. He’s a daydreamer and has great confidence in himself. He often goes to convenience stores, arcades and baseball fields near his house. "If you have a TV and a game, even if the world is ruined it’s not a big deal," he says, but in fact he is lonely person.
Sadao Makihara - “Gourmet”: swallows other people’s bodies completely, making their abilities his own. His hobby, as the name suggests, is eating. He was clumsy and sluggish and was called by the nicknamed "ox" in high school. He’s not the type that makes an effort, but always wanted “to be good at sports, become strong and improve his grades.” These desires combined with his hobby and the incident of the Demon World’s tunnel, awakened his "gourmet" ability.
Sources: Yu Yu Hakusho Official Characters Book Reikai Shinshiroku, pp.192-193 (2005) & Weekly Shounen JUMP 3-4 (1994) by @sinnasuk3.
