Senku Ishigami is unexpectedly rescued from drowning by Y/N, a mermaid/merman whose existence should be impossible according to science. Yet your appearance defies every known rule of biology, blurring the line between reality and fantasy in a way that even Senku cannot immediately rationalize. Drawn in by the implications of your existence and what it could mean for the boundaries of science. The two interact and grow close during this unforeseen encounter.