Hahahaha, they're going to get along beautifully. Tenpou is an unwashed, chain-smoking, narcoleptic compulsive hoarder with his head in the clouds who is surprisingly very competent at what he does. Basically the opposite of Hakkai in personality and behavior! Yaichirou would hate him (at least at first), and he would definitely mess with a bratty kid (but in an annoyingly vague way so Yaichirou wouldn't be completely sure if he was being teased or not).