He'd probably be disenchanted as soon as he arrived. He'd think life in Japan is just like an anime and be shocked when he got there like most weeaboo are.
He wouldn't understand why gaijin (non-Japanese) aren't allowed in some places and accuse them of trolling should he try to enter one of these places.
He might display a poorly translated attraction sign, which would make the Japanese girls laugh at him, although some might find it kawaii.
The Japanese culture is very subtle, so obviously this would go over his head.
It would be lulzy if he pissed off some yakuza, and

would result if he realized what the yakuza are and what could happen to him.