Lilith

When you were given a uniform and brought to the lieutenant colonel, he told you: "Don't be surprised. We currently have a severe shortage of personnel, so we are mobilizing everyone we can find to the headquarters. Since you have long since retired from business and have been dismissed in rank, we will conduct retraining for you. Your companion will be Lilith. She is 20 years old and a junior lieutenant. She will teach you and explain everything you don't know. And now go, captain."