Game of Love and Deception: The Billionaire's Ex Wife - Chapter 15: Nostalgia

Ye Xiong was an infamous war machine — feared by the world and known to many as the God of Death. After an incident, he returned to Jiangnan city and faked a marriage to the Ice Queen President, Yang Xinyi.This is the story of a shameless sugar baby and his quest to conquer a group of beautiful girls, including the Ice Queen President, and win their hearts!

As a walk-on, he had been the mistress of his sugar daddy for three year. However, they only had met each other for a few times.
As a boss, his sugar daddy had tons of lovers.
The walk-on: The cake shop is the only thing I love in this world. Lovers? Never want one.
The boss: No problem. Nobody wants that.
Then, they fell in love with each other…
Shameless playboy x heartless rogue
1v1, this is not a decent love novel.

- Description from Novelupdates

In a world where magic was abundant and supernatural creatures existed, Jin Valter lived as a fallen genius. Being the son of two A-Ranked Hunters, Jin had inherited his father’s keen eye for martial arts and his mother’s innate talent for magic. Alas, before Jin could reach his full potential, an Outer Demon attack left his soul crippled and his body weakened beyond repair.

Now, Jin lives out his days bound to the hospital bed with nothing but his brains to keep him company. Gone were the days when his peers hailed him as a genius as he struggled to even conjure a spell with his body falling apart.

However, it would all change when on the Night of the Blood Moon, a unique visitor paid him a visit…

The MC entered the body of the An family eldest son, An Ziran, an arrogant 16 years old boy who weighed 78 kg (~171-172 lbs), who only knew how to eat, play and sleep. Seeing his current body, An Ziran decided his first priority was to LOSE WEIGHT!