One day, ordinary office worker Kubo Tamotsu is suddenly reincarnated in another world as a 6-year-old slave. The household of the Basam Marquess, who raised him as a Barrier Master named Linus, gets caught up in the Royal Army's rebellion and falls. Desperately overcoming his grief, Linus begins a new life in the neighboring Hideta Empire. One day, while resolving trouble concerning the First Princess and helping a pretty demon girl, he meets a beautiful part-human, part-sheep woman in the slave market...
