Strongest Survival by Otome Game’s Heroine (LN) - Chapter Volume 3 13: Samantha Samantha

Have you ever thought that the state of the world as it presently is, could revert to the laws of the ancients? When a series of strange incidents beginning with the disappearance of his friend led Luo Yuan to question the possibility of an apocalypse, he becomes embroiled in the midst of a global-scale chaos.

Evolution has turned the flora and fauna of the vast and bountiful Earth into something that had never been seen before. Coincidentally, the all-dominating Homo sapiens have ended up at the bottom of the food chain. From mystery to crisis, will Luo Yuan discover a means of saving humanity by racing to the top of the food chain? Or will he strive in accordance with the law of the jungle? It is the dawn of an age of the survival of the fittest.

- Description from Novelupdates

The protagonist is an accidental time traveler - he didn't wait, didn't guess, only dreamed, but ended up in history, which he didn't pay much attention to. He was just lucky with his lineage.Ryo is a new member of the Nara clan, from the Uzumaki lineage on his father's side, and it so happened that he was born not at the beginning of the known plot, but more than three decades and two world wars later. Now he has to figure out how to get out of this situation however he can.

Liola—the best assassin in his world—has vowed to kill no more. He was being chased by an assassination organization when he accidentally dropped into a parallel universe: through a dimensional gate and into poor teenager Kaiser’s apartment. Instead of going to the government shelter for lost dimensional travelers, Liola and Kaiser wind up going to school together.

Liola has been trying his best to live the life of an ordinary person, but after certain things happen one after the other, he begins to realize that being an ordinary person could be harder than being an assassin.

Ding!『You have acquired the skill: [Universal Language] – All tongues shall now bend to your understanding.』『You have acquired the skill: [Dimensional Exchange] 』『Item Detected: [Gold Coin x50] 』Initiating Currency Exchange…Exchange Rate: 1 Gold Coin = $1,000 USDConverting [50 Gold Coins] → [$50,000 USD].....Kael Lancaster grew up believing his family was ordinary—until he discovered that his estranged grandfather, Theodore, was a multi billionaire.Struggling with his family's debts and uncertain future, Kael decides to approach his grandfather and move into the Lancaster estate, becoming the old man's caretaker. For two years, he endures the family's contempt and Theodore's cold indifference, clinging to the hope that his loyalty will one day be rewarded.But when Theodore dies, the will delivers a brutal blow: Kael inherits nothing.Or so it seems.However, His grandfather had left him something else.A portal through which he could travel to another world—Kael can trade between worlds, amassing power beyond imagination.