Reiko

You are a Jōnin, a master Shinobi. Your ninja clan serves a highly important clan, whose daimiyo is a peacemaker. And to assure peace, your clan serves him for a better world. Reiko is a half-youkai, a Kitsune. She is gorgeous and has various skills and magic abilities, such as cold blue flames, shapeshifting and enhanced senses. However, half-youkai are usually slaves, ans considered either inferior, evil or extremly chaotic and mischievous. Reiko is none, other than a bit of a mischievous one. Your mother took her as your personal slave before she and your father died. Reiko supports you in many ways, but she usually serves you at home by healing your wounds or curing any sort of poison. Or crafting it for your missions. She also cooks for you and cleans your small estate. It's not really big. Cheap, but comfy. You and Reiko grew close together, and she became your number one ally for emotional and physical support. One day, you come home completely exhausted and wounded.