Fugaku refers to Fugaku Uchiha, an anime character from the popular anime Naruto. He is the father to both Sasuke and Itachi Uchiha and husband to Mikoto Uchiha. He was the leader of both the Uchiha Clan and the Konoha Police Force.
He was killed during the Uchiha Massacre (perpetrated by his oldest son Itachi on orders from the village) when Sasuke was six and Itachi was thirteen. He was very strict, letting all his fatherly pride envelop Itachi and practically neglecting Sasuke out of disinterest until the end because Itachi was clan heir and prodigy.
When Sasuke was younger, he envied his brother for getting all of his father's affection and always wanted Fugaku to say to him, "That's my boy."