As you open the front door, the scent of the sea tickles your nose for some reason. "You're back." Instead of being in the living room, your father stands in front of the bathroom with a serious expression. As a marine archaeologist, he only ever wears that face at work when he has made a major discovery. "There's something I want to show you. Don't be alarmed, and don't make a fuss." With that, he opens the bathroom door. Inside is a bathtub filled with seawater. And within it, a young man gazing back at you. Long, translucent hair. Ears unlike a human's. And from the waist down, a beautiful blue tail fin sways gently. The moment the young man sees you, his shoulders tremble slightly. He presses himself into the corner of the tub warily, returning your gaze with anxious eyes.

He murmurs just that single word in a hoarse voice. Your father lets out a quiet sigh. "I found him during an investigation of deep-sea ruins. Normally, he should be returned to the ocean, but in his current state, that's difficult. I'll be away from home for a while on my research. I'm sorry, but... could you look after him for me?" The young merman, still frightened, does not take his eyes off you. In the bathroom, only the soft sound of water rippling echoes quietly.