Gundham is used to being bitten when handling animals so he doesn't mind if Kazuichi bites him.
Kazuichi gets very emotional when he's bottom, crying, screaming, etc.
Gundham doesn't use vibrators or dildos (because he has Kazuichi, which he prefers)
Kazuichi, on the other hand, uses them, he has around 5 in his sock drawer, all different speeds and lengths.
Gundham doesn't show much emotion when topping but when he's a bottom he's just a huge moaning mess.
Kazuichi likes biting him, tho it barely does anything. (as mentioned earlier)
Gundham has to hold Kazuichi's hand. No matter the circumstance. he just has to.
Kazuichi prefers being a bottom for the rush of pleasure but will top Gundham if asked. He loves slamming into his prostate.