So first it's a slice of life, don't go in expecting alot of action, it's mostly business work inventing new items.
There is slavery and in fact most of the characters on the cover are technically the mc's slaves, however i should point out that there does seem to be some kind of civil rights for slaves in this series, in that the buyer has to treat them essentially like a worker, provide medical treatment, sane work hours, proper meals and housing etc (i believe they also have to be paid a basic amenities fund for entertainment but i don't think that was ever explained well, and i believe buying themselves out of it is also a possibility), mistreatment of a slave is grounds to have the contract annuled and slave merchants tend to be rather protective of their slaves anyway, basically the biggest part of the slave contract is they can't quit without good reason and they cannot sell secrets of products like new items or gear due to the pact they must always tell the truth and not betray their master essentially.
The tldr of it is that slavery in this series is closer to indentured servitude, aka paying off a debt, your required to treat them as humans and not as property and the slavery part is more of a work contract, mistreating them besides being a crime (slaves have human rights in-series) carries harsh penalties.
The mc is a typical japanese main character so be prepared for that stupidity.
This is not high art either, it's a bit above average but not on the level of something like tsukimichi or reincarnated as a slime. |