Star Eater - Chapter 557 -

Xiaya reincarnated in the Dragon Ball Universe as a Saiyan 12 years before the destruction of Planet Vegeta.

Watch him as he creates the strongest legend of Dragon Ball World from the beginning.

- Description from Novelupdates

Kōdo Ikusei Senior High School, a leading prestigious school with state-of-the-art facilities where nearly 100% of students go on to university or find employment. The students there have the freedom to wear any hairstyle and bring any personal effects they desire. Kōdo Ikusei is a paradise-like school, but the truth is that only the most superior of students receive favorable treatment.

The protagonist Kiyotaka Ayanokōji is a student of D-class, which is where the school dumps its “inferior” students in order to ridicule them. For a certain reason, Kiyotaka was careless on his entrance examination, and was put in D-class. After meeting Suzune Horikita and Kikyō Kushida, two other students in his class, Kiyotaka’s situation begins to change.

Dear comrades, masters, priests, masters, fairies, demons, and leaders, welcome to my world and enjoy the supreme pleasure and supreme enjoyment brought by traveling through various worlds (funny laugh).

- Description from novelbuddy

Ruins stretched across the landscape in the apocalypse after the nuclear war.