Hey guys couldn't see a thread for this game if anyone else plays feel free to add trading related posts.
Only trading methods I know are timespace delivery system you can send items 2 star and under. You may first have to play with that person before trading to see in recipient list. So add each other play a PQ quest together and you should be right from there.
There's also ways to backup your data to cloud or usb and send item then re load backup and you still have item you just sent. I have not tried this though so if someone else knows more and can clarify please post!