the protagonist of "utawarerumono: mask of deception". an amnesiac found wandering in the mountains in a hospital gown, he is found and nursed back to health by kuon, and subsequently taken care of by her when she finds that he is physically extremely weak by demi-human standards, being unable to perform simple tasks that even children are able to do easily. it turns out that this is due to him not being a genetically enhanced demi-human, but a regular human who was recently awakened from cold sleep. the mikado/emperor of yamato later reveals to haku that they are brothers, the mikado having survived all this time through human experiments he had performed on himself which extended his lifespan. when oshtor dies after defeating vurai in a duel, haku decides to take on his mask and pretend to be him in order to protect anju. before entering cold sleep he was a skilled hacker, and he was the one who stole the data on the iceman project which allowed his brother to create copies of hakuowlo's mask, enabling the events of "mask of deception" to take place.