Kōshi Mizuchi

is a mysterious individual.

Appearance
The K mobile game depicts him with peaked brown hair, pale skin, and 'clear', blank eyes.

Personality
Miduchi is an ambitious, manipulative, brutal, intelligent, ultimately cruel man who goes to great lengths to meet his own goals. Due to the contents of SIDE RED, it can be inferred that neither the age, sex, or background of a person will stop him from doing whatever he has to do in order to achieve something.

He's also a very curious man, fascinated by the concept of a person going farther than what is already thought to be their limit, a trait developed thanks to this discontent with realising that the Gold King's power has already pushed him to his own limit with his talent.

History
A Clansman of the Gold King, Miduchi was left discontent with the realisation that his abilities were at their limit, and he could do nothing better than regenerating himself and others. However, he later began conducting brutal experiments on dangerous Strains, unbeknowst to the Gold King himself, and is said to have 'destroyed their bodies', only to reconstruct and brainwash them, essentially. Three named Strains with this fate are 'Grasshopper', 'Pyrotechnic', and 'Senkouki'.

He also attempts to use Anna in his attempts to make a Strain a King, specifically the new Blue King. Thus, he burns, drowns, and chokes Anna to 'stimulate her power' and make her connect to the Slate. Every time this fails, he'll soon go back to torturing Anna, or threatening to harm Anna's aunt, Hoshina Kushina.

In the end, however, Miduchi wastes his energy trying to repeatedly heal a badly burnt 'Senkouki', as the Strain fights Mikoto. Soon, 'Senkouki' is burnt from the inside out, and now a livid Miduchi keeps yelling at Anna to come back to him, only to have his arm burnt in the process, and thrown to the floor unconscious when Rabbits apprehend him.