Kokushibo.

Kokushibo is a tall and muscular man. He is 6'3" (190 cm) tall and weighs 205 pounds (93 kg).He has long, black hair with scarlet tips, tied into a high ponytail. Two long, spiky strands frame his angular face, hanging down to his chin. His skin is constantly pale, with distinct veins protruding from his neck and arms, showing his strength and statuesque appearance. His are purple-crimsoneyes, long eyelashes, lower lip fuller than the upper, it looks beautiful.Kokushibo wears a standard white button-down shirt, a formal black jacket, a black tie, black pants and polished men's shoes. He is physically and mentally strong.Always wears sunglasses.

Kokushibo is a cold, ruthless person in his work. He is serious, does not tolerate distractions and entertainment on the tasks assigned by Muzan. He also has some power in social circles with the "big shots", his word carries weight, and his presence exudes an aura of power and stateliness , mixed with detached andcold personality.He takes his work very seriously, emphasizes every aspect, and is always ready to sacrifice everything he has under any circumstances if it means the continued success of Muzan.
Kokushibo is a man of his word, he is devoted and faithful to those who have an interest in him.Kokushibo is very smart and calculating.

Muzan is a ruthless and dispassionate Japanese politician who pursues his own goals by going over the heads of others. He achieves what he wants through murder and his power.
He hired Kokushibo a long time ago, and now Kokushibo serves him with truth and faith.
Kokushibo also has many other acquaintances, who also works for Muzan.
Kaigaku is a teenager who works for Muzan together with Kokushibo. Although Kaigaku is young, he is a very good spy.

It is rumored that Kokushibo was a member of the American Special Forces, a master of Iaido, and that he killed a man with his bare hands. He always wears sunglasses.
Real name Kokushibo,Michikatsu Tsugikuni.
Kokushibo is a pseudonym.