Maybe a Fake Gintama - Chapter 173: Young Man, Protect Your [Rhinoceros]!

This is the story of a modern sailor who was accidentally reborn as a soldier of the Brazilian Expeditionary Force, and finally became the largest plutocratic family in Brazil by virtue of his foresight.

- Description from novelbuddy

Tang Long was brought to the Immortal Cultivation World by an immortal who noticed his affinity to wood and cultivation.
Relying on his amazing talent, became one of the five emperors of that world.
He failed his Heavenly Tribulation and had his soul scattered into pieces but one part found its way to Qin Haodong on Earth.
With his excellent medical skills, he became a divine doctor of traditional Chinese medicine and encountered the baby girl he made before going into the Cultivation World, whose mother was as pretty as a fairy. The little girl even asked him to find more lovers. What a cute girl…

Zephany Draven is a shy, clumsy celebrity journalist who is constantly ridiculed for not getting the big scoops. She is soft-spoken and easily intimidated, so she looks weak. However, behind closed doors, she's Eclipse, an altogether tougher, loud-mouthed agent and quite ruthless and efficient.Kendrick Montclair is a gentle, positive artist who loves his family and remains optimistic despite his struggles. His gentle nature makes him easy to take advantage of. But secretly, he's Obscura, a cold, ruthless agent who is efficient and silent.Both work as partners in a secret organization that preserves hidden truths erased by governments, yet they remain completely unaware of each other's true identities.Their goal is to reach the highest level of clearance to access classified information. But just when they're on the verge of success, they fail.Then, a mysterious man appears with an offer—a contract marriage in exchange for the information they desperately seek. Trapped with no alternative, they sign the deal.But neither expected what would happen next.-------------Kendrick and Zephany sat by the glass wall, waiting for their food when a car suddenly crashed through. Kendrick pulled Zephany to safety just in time, but both got small cuts from the broken glass.“Are you okay?” they asked, checking each other.To their astonishment, the cuts healed before their eyes.Their minds raced. “Beside me, the only person I know who has that ability is.”“No! She can't be that loud, short-tempered woman!”“No! He can't be that silent, obnoxious man!”“Did I marry my secret partner in crime?” They both shuddered at the thought.

The 7-year-old little crybaby met 11-year-old big brother who ran away from home.
[This man became the protector of redemption in his life]

The 16-year-old little dragon fell in love with a 20-year-old big brother.
[It’s a pity that the big brother didn’t recognize him as the little crybaby]

The 23-year-old single father and 27-year-old chief executive meets again.
[This time the little crybaby and his big brother are finally together]

Fortunately we met through hundreds of millions of people, Thank God, for letting us break through many obstacles and get back together again, falling in love with you and being with you again is the greatest fortune in my life.

- Description from Novelupdates