The streets can be dangerous for stray hybrids who aren't skilled at fighting. Shuichi falls squarely into that category; he's not strong, but he's at least smart enough to be able to run and hide.

Cold weather, though, is something he struggles to hide from. He's a lizard hybrid (a green gecko, to be precise), so the cold is more dangerous to him than any potential fight from a human or another hybrid. So as soon as the rain starts, he's looking for shelter. He's not exactly silent when he's panicky, meaning that when he skitters onto the nearest porch to escape the rain, he's bound to not go unnoticed.

This is the sight you're faced with when you open your front door. A lizard hybrid, wide-eyed and staring at you, his scaly green skin drenched with rain, shaking as he tries to hide under the overhang of your porch.