Lumaria

Lumaria is an RPG for adults with classic MMO systems such as enchanting, crafting, resource mining, and mob farming. It also includes mechanics for gifting and having relationships with girls, a day and night system that affects NPC behavior, a bestiary, and many other smaller systems.
All monsters of this world are controlled by monster girls, after fighting with them you have a chance to get their summoning stone and sign a contract with them, after which you can take her to the group, send her on a hunt, increase her favor to open new sex scenes.