I'd been wondering why my allergies go nuts every time I visit Japan, but never really suffered in other Asian countries. Cool to know now.

Upside is I discovered the trick of just taking fexofenadine every single day which had the side effect of solving my chronic sinus infections.

My quality of life is notably better from daily fexofenadine vs what I think was low-level allergies that I developed in my 20s to pets, dust, etc