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I was invited to the home of a senior from my university days. He seems to be happy and married to a wonderful wife. It's been a long time since we met again, and while we're talking about memories, it gets late at night, and I decide to stay at my senior's house, but in the middle of the night, I witness the masochist training of my senior and his wife. The next day, my senior left home for work and I was left alone with my wife...