Long story short, you have to:
- Mail all the gear you want to keep to yourself in Canada. Cheaper than paying the flight surcharge, and even if the items aren't prohibited they will raise issues at the various checkpoint in airports.
- Sell or abandon gun, grenades and other prohibited items. Look around the newb tank for the list of what is ok and what is not.
- Move, panic, settle in, get your affairs in order.
- Get in touch with your local group, meet an age verifier.
- Once your AV status clears, you'll have access to anything. Keep in mind that you will pay Canadian prices, around double what you had in Japan.
Some might suggest bringing in the guns without the restricted receiver parts, bad idea, the market for bodies and frames in Canada, apart from ARs, is practically non-existent.
The transparent frame/receiver thing is to help importation, but there are other ways to get guns in. It's not practical for an individual to do though.
TL;DR airsoft in Canada is a tad more complicated than in Japan, network with people once here and they'll get you up to speed.