Togurikoru and his son Nero.
Togurikoru is the chief warden of the labor camp where women who have had an "illicit love affair" mine houseki, in Svelera. The day of his arrival he sends for Yuuri and then has him play with his son, Nero. Later on, when Yuuri talks about how wrong it is to kill babies and force women to work like that, he asks if Yuuri is a preacher.
Ue-sama, gave him the nickname Mr. White Mohawk in the manga. In the novels, Yuuri calls him Tricolor because his hair, eyebrows, and beard have different colors.