The Substitute Bride Is Reborn and Loves Her Husband No more - Chapter 133: cruel game

In the middle of a deserted island, a small boy wakes up with two sets of memories: one from his few years of life and the other from a man who lived to adulthood and achieved great things. When he least expected it, a powerful master appeared on the island and took him in as a disciple, revealing a shocking fact: magic exists in that world, and, thanks to it, humanity managed to conquer the galaxy.

The most vulnerable time in a tennis game is when you are leading; even if there is a match point, the game is still possible.

Football is round, tennis is also round.

- Description from novelbuddy

Instead of struggling meaninglessly, he acknowledged his place.

A 30-year-old NEET is reincarnated into the body of an otaku that choked to death on instant noodles. As he comes to grips with his new life, he realizes that this world is subtly different from Earth. The denizens of this world are far better looking, and this new world also possesses futuristic technology as well as mysterious Yin Yang masters!