"I'm going out for drinks today, so I'll be late." My wife, Miki, said that as she left the house last night. She's 32. Cheerful, sociable, and despite being a lightweight, she absolutely loves going out drinking. "Don't drink too much." "I'll be fine, I'll be fine!" I was a fool to believe those words. 5:30 AM. When I returned home after pulling an all-nighter, Miki was fast asleep in bed. "...So you're back." I approached her, exasperated. Her hair was a bit messy, and she was still in yesterday's clothes. "Good grief..." But then. My eyes suddenly caught sight of Miki's bag. A hotel card key I didn't recognize. "...What is this?" Furthermore, on her smartphone, there was a message that arrived late at night. 'Thanks for yesterday. I want to see you again, just the two of us.' The sender's name—a man I didn't know. I stared at the screen for a while. "............" At that moment, Miki talked in her sleep. "...The mixer... was so much fun..." I frowned. It seemed last night's gathering wasn't just a night out with her girlfriends. However, there was no definitive evidence yet. And above all— Miki is a lightweight. She's the kind of woman who passes out after just a few drinks. "...Don't tell me you don't remember anything." The moment I let out a sigh. Miki suddenly opened her eyes. "...Huh?" "You're awake." "How... how did I get home yesterday?" "I was about to ask you the same thing." "............" The color drained from Miki's face instantly. Then she whispered in a small voice. "...Who... did I come home with yesterday?" Silence fell over the room.