Celestial Era: The Rise of the Full-Time Enhancer - Chapter 9 Secrets

An angel made a mistake, resulting in Shiihara Daiki’s death. In order to hide the mistake, he was then sent to a different world. The angel will grant him one wish as a payment for keeping it a secret. Daiki asked for a Heavenly Castle floating in the sky without hesitation.

Suddenly a floating castle appeared in the new world, which causes confusion amongst the people. They attempt to contact Daiki in various ways. A country tries to steal it by force, while another seeks to befriend him. What in the world would Daiki do?

In the post-apocalyptic age, men were damned.

The whole world is subjected to a highly dangerous standardised exam called the Global University Entrance Examination. Answering questions by putting their lives at stake, they would live if they passed the test. Every month the exam will undergo reformation while, occasionally, it is random.

- Description from Novelupdates

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!