Houko Yamiguchi (闇口 崩子, Yamiguchi Houko) is a runaway kid living in the Antique Apartments, former assassin of the Yamiguchi Family, and the half-sister of Moeta Ishinagi.


Houko has a nice and polite personality, and is decribed by I as pure and innocent. Her big brother is very protective of her. She has a bad relationship with her mother, Hyoui Yamiguchi as well as her father, Kajumaru Rikka. She develops a sort of master-servant relationship with I, doing her best to help him.

She doesn't go to school, but she goes to the library every day. Often falls asleep in vehicles. Her hobby is killing small animals, and her favorite place is Kamogawa park (she likes the ducks and pigeons).


Houko is a petite girl with short black hair in a bob haircut and big black eyes. She wears a white dress tied at the back with a polka-dot patterned black ribbon, and white high-heeled shoes.


Houko was born in the Yamiguchi Family, the second most powerful Killing Name, to Hyoui Yamiguchi and Kajumaru Rikka, who also fathered Moeta, a member of the Ishinagi Family.

When she was 10 years old, she ran away with her half-brother, and found the Antique Apartment, where the two remained.


Psycho Logical (Part Two)Edit

After I returned from Kyouichirou Shadou's Laboratory, he ran into Houko, who was busy killing some bugs, while going to university.

Cannibal MagicalEdit


  • Yamiguchi can be translated to "mouth of darkness" (闇, Yami = Darkness; 口, Kuchi = Mouth).
  • Houko, her first name, can be translated to "crumbling child" (崩, Hou = Crumble, Die, Demolish; 子, Ko = Child).
  • Her birthday is April 16th.
  • Her weight is 32 kilograms (70 pounds), and her height is 138 centimeters (4 feet and 6 inches).


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