Slave Companion in Fantasy/Isekai (PART 1)

Story has a Slave that travels with the Protagonist on their adventures. Includes Ex-Slave/'Released from Slavery' tag after the story begins.

(PART 2) here

Adventurer party/Hero's Party in fantasy/isekai
here
Underestimated/Overpowered Protagonist in fantasy/isekai
here

Story with lewd activities in fantasy/isekai
here
Polyamory in Fantasy/Isekai
here