Intuitive Conclusions (sharp teeth of truth) - 14 - Future, Decimo Era
There's a particular bonding condition that Tsuna doesn't think his Guardians fully understand, not all of them or even most of them. It did not click for them, because it was not a thing that Tusna spoke of to them, not a thing that they went through together.
It is hatred.
Specifically, hatred of one's father.
Now, it's not a secret that Tuna doesn't like Iemitsu, but - Tsuna's anger had always looked sharp and bright and loud to everyone around him. They've seen him snarl and shout and scream at Byakuran, Jaeger, any enemy who really pissed him off at the time.
His emotions are smoother these days, because he's older, but he still seems warm.
Tsuna's hatred is cold.
It's an abyss and bite of Zero-Point ice. It's cutting and precise and so very quiet.
So while all of his Guardian know that Tsuna is cold to Iemitsu, not all of them realize that Tsuna truly hates him. Ones who seem to have noticed it most clearly are Hibari and Lambo. Mukuro as well, after his last assignment.
Though only Mukuro seems to have understood that this was a bonding condition all of Tsuna's Guaridans achieved. Hatred of one's parent, more specifically, their fathers.
I makes Mukuro side-eye Yamamoto Takeshi for a full week.