Seido Tsuyoshi is a character in Go Lion, an early 80's anime, and was the basis of the Voltron character Hunk. A member of the Go Lion team, he pilots the Yellow Lion and goes by the nickname Hothead. Large but not fat, he is also neither slow nor stupid, and Seido's determination is not something to get in the way of. He is enormously protective of the helpless. He'll eat you out of house and home, but give you the shirt off his back, all in the same heartbeat.
Seido is both anchor and counterweight to the team. His tendency to eat and rest in large portions reminds the hard-working group that a break must come. He is not as sure of himself as Kogane, nor is he quite as quick to anger as Kurogane, though once his fuse is lit, he's even harder to dissuade from a rash course of action. He's neither stoic like the late Shirogane nor determined to prove himself like Princess Fala, but he will control himself when needed and he will not shy from a challenge. His strength and size complements the skill and speed of Suzuishi Hiroshi, and he is generally the easiest to get along with, even serving as the Princess' escort to a celebration while also keeping her safe. If Seido has a fault, it's in keeping focus, but this ties into his large heart.
Few changes were made when Seido was transformed into Voltron's Hunk, except maybe for the character's qualities having more of a slapstick comedic tinge to them.