While stationed in Yokosuka, Japan, after World War II, Miller had a relationship with a Japanese woman, who had been prostituting herself to the occupation troops in order to survive. He treated her like a wife until he returned to America, leaving her with some money, but never writing to her afterwards. It was after Miller had left that his son, Kazuhira, was born.
Sometime later, Miller retired from active duty and became a military instructor in Virginia, with at least one of his students being dispatched to Japan where his son later learned this. Miller then received a letter from his son asking to come to America. Miller responded and accepted the request, making the travel arrangements for him. However, around that time, Miller had fallen into a state of depression after his American son was killed in the Vietnam War and his wife divorced him, and had also retired from teaching. Following their reunion, Miller gave Kazuhira his family name as well as some money for college, although he refused to see his mother. At some point during this time, he also told his father about his being an American. A few years later, Miller committed suicide, reportedly shooting himself in the head.
Behind the scenes
Colonel Miller is mentioned in Metal Gear Solid: Peace Walker, described by his son, Kazuhira, in the Briefing File "About himself: Upbringing." While Kazuhira implies that his blond hair and blue eyes were inherited from his father, it is not clear whether the senior Miller expressed these traits himself. Aside from the briefing file, Miller also referenced his dad while sleeptalking in the Extra Ops Mission Date Kaz, where he tells him his American nationality.
- Metal Gear Solid: Peace Walker (mentioned only)
- Metal Gear Solid V: The Phantom Pain (mentioned only)