First of all, I wish I can read the novel because the storyboard for the manga is so messy.
I have read a similar Chinese novel with almost the same premise BUT it is mostly about how MC will pick up with what is left with this now 'life'. It is about an MC having his body 'abducted' by a system transmigrator for several years. That transmigrator turned his life worse (going OOC from MC's original personality). Now that MC came back he is building his life with a mental age from when his body was taken.
Theres a shoujo manga with a similar concept, the mc body was swapped with a Japanese girl when she was 12, the girl thinking it was one of those isekai novels ruins her life and married the duke of the north a suffers a great amount while the mc live a good live and becomes a doctor, now into adulthood they swap back and needs to survive in the mess the previous girl left, it was good at the start but became bad later









Coming here because of the anime adaptation. The episode 1 ending was so funny. They really have to point out that the manga was made in 1995 and there are outrageous scenes/triggers..