Mukuro was the result of an experiment of the Estraneo Famiglia's selfishness.

Mukuro would thought that it was an irony that the one they created to be used as a weapon would be the one who destroyed them in the end.

But because of his...... inhuman ways of killing those bastards that don't deserve to walk on this planet, he became a fugitive of Vindice, taking along two other kids who were the same as him.

He had escaped Vendicare, a place said to be the most unescapable prison, and had made plans to bathe the world in chaos.

He bid his time, controlling people who he thought would play an important role in starting a war.

When he heard about a boy being chosen as the tenth boss of Vongola, the strongest mafia, he knew that he must possess that boy.

Imagine his disappointment when he saw a weakling, a boy who fears almost everything, was chosen as the next in line. How Vongola has fallen.

But it turns out he was completely wrong about the boy. Sure, he's a coward and naive, but that boy had the strongest resolve when it comes to protecting his friends. His pure and forgiving heart was too much for Mukuro's black and tainted heart.

As he was dragged away by the Vindice, that boy's eyes held a resolve in them as he stared at Mukuro. For what reason, he doesn't know. And he doesn't care.

Trapped in that dark and cold water tube, he found a way to go outside through a girl who was on the verge of dying.

In exchange for saving her life, she became his vessel should he wish to appear. Somewhere at the back of his mind, his thoughts said that he saved this girl because he pitied her. Mukuro quickly banished such ridiculous thoughts from his mind.

When he made his appearance through Chrome, his vessel, he was honestly surprised when Tsuna trusted him. He immediately dismissed that feeling as he retreated back to his dark and soundless world, not wanting to believe that he had started to trust again.

But after countless of times, slowly but surely, Mukuro began to trust Tsuna. Tsuna's honest action had somehow reached his black and lonely heart and was able to drag it back into the warm and blinding light.

His trust had somewhat deepened after his body was released from Vendicare prison, and it was all thanks to Tsuna's unwillingness to destroy the Shimon Famiglia.

Now that he became Tsuna's Mist Guardian, he can't help but laugh at the irony. He, who loathed the mafia and wished to destroy the world, is following a man who is the boss of the strongest mafia family and is on his way to make the world better.

That's why, he thought, that this white flower would fit Tsuna perfectly like a glove.

A pure and untainted heart that would light the darkness.