Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e - Volume 15, Chapter 1: Intro - Secret Maneuvers

“Seven years later, she returned with her baby

”Give me the child, and you can name a price!“

”Spring only sows the seeds. When it comes to autumn, you want to obtain a son. Heh, man, aren't you thinking too simply!“

”If you want me to call you daddy, then you have to show your ability to chase after my mommy. The man that my mommy likes is my daddy! “Otherwise, there's no need to talk about it!”

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

Traversing into a Fantasy World, Watson became the youngest son of a run-down baron, ranked eight in the family.