Gotou manages the Zoldyck family and essentially acts as the gatekeeper for any contact with them. He's best known for being genuinely intimidating—so much so that Killua's described having recurring nightmares about him chasing him with a knife. Despite that terrifying reputation, he actually cares deeply for Killua, treating him almost like his own son. He's also weirdly skilled at magic tricks, specifically the "where is the coin" bit. There's something enigmatic about him that makes it hard to pin down exactly what he's thinking, but his loyalty to the family—and to Killua—is pretty clear.
Content compiled by AnimeList.moe from publicly available sources.
