Became the Unjust Contract Slave of the Archamage's Book - Chapter 10

Leon Walker, the world-weary genius of modern world, is killed in a freak accident — the notorious Truck-Kun makes an appearance. Death is only the start. He finds himself reborn in a new world, Galvia, reincarnated into the strong but failing body of Duke Leon Moonwalker, one of the only three Grand Dukes of the Moonstone Kingdom, a minor but strategically powerful kingdom within Galvia. As Leon attempts to understand his new world, a strange voice resonates in his head. “Supreme Spouse System Activated.”.

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

The fiancée has betrayed, but how could she know that the man she looked down upon was in fact a prodigy with healing and martial prowess!

Reborn as the ill-fated Third Kazekage from the original series, I am determined to rebuild Sunagakure into the strongest Hidden Sand Village through tireless effort and visionary leadership. My goal is to survive and thrive in the recurring Shinobi World Wars.I will show these ninja, who are obsessed with slaughter and conspiracy, what true 21st-century wisdom and modern governance look like.The world of ninja is not a story written solely by Konoha.