First, a key point: the pairing in this story is Qin Shi Huang x the Tenth Generation. If that's not your thing, don't read! Please keep to your own corner and enjoy it. Everyone getting along is what really matters.
Synopsis:
Young Sawada Tsunayoshi doesn't understand why everyone else has a mom and a dad, while he only has his mom. The children around him don't want to play with him and call him a wild child nobody wanted because he has no father. But his mom clearly said, "Daddy went to earn money to take care of you and me, Tsuna."
Tsuna can only keep telling himself that he isn't a wild child nobody wanted.
Later, he meets an older boy in his dreams. The boy only has a mom, too, but unlike Tsuna, he can fight back when he's bullied. He even teaches Tsuna how to fight back and how to be a strong, responsible boy who takes care of his mom... Tsuna really, really likes him!
For a long time during his childhood, Zhao Zheng dreams of a silly little brat who just cries when insulted, can't fight back when bullied, and is stupid with bad grades. The kid isn't good at anything, yet he always sneaks glances at Zhao Zheng with shining eyes, quietly cheers him on, and tries to help however he can. So Zhao Zheng gradually lets the kid stay by his side, teaching him when he has nothing better to do.
Later, Sawada Tsunayoshi is pushed into learning how to become a leader: the Tenth Generation Vongola, godfather of the underworld. Later, Zhao Zheng becomes Ying Zheng, battling his way through thorns on the road to the throne.
They both ascend to the throne and are crowned emperors.
P.S. 1. Mutual healing and mutual growth.
2. The emperor can be imagined as he appears in Qin's Moon and The Nine Songs. The history is somewhat fictionalized.
3. The Guardians and Tsuna share a bond of friendship above all else.
4. I just made up the synopsis. I may revise it later.
Theme: No one is perfect, but we can grow together and become better.