William Yeah - yeah, this is the guy. If I held him in a splayed hand, he’d overflow my fingertips. Funny thing is he scuttled to a spot mid-wall, as if that would make him invisible. Spiders are not known for their intelligence. This guy is an アシダカグモ (“big-legged spider,” probably as they have big friggin’ legs), or Heteropoda venatoria, or huntsman spider. Here’s the good thing: they are totally not interested in you, but they will eat every single cockroach that they can detect with eyes on top of their head which can see even behind them. So while you might be startled to see one, leave him alone and the next morning you’ll be delighted to find chunks of cockroach husks on your genkan floor.