Japanese Mon coin [opgelost]

Hiya, got this recently. I have some doubts about it being real.

Weighs 2.1 (give of take about 0.1) grams, and is about 22mm in diameter. Seems to have a wider hole than the Mon coins I've looked at too

Doesn't look off to me. There is a large variants in diameter, weight, material, calligraphy etc. for Kanei Tsuho. They were made buy countless official (and unofficial) mints over centuries.

Makes sense, just being paranoid since it's my first older Japanese coin :)