Square Enix (JP) mobile games usually offer beta before launch. Most beta, however, are open to Square Enix (JP) members only. Here is the way to registering for an account in case you really want to try a game before it comes out!
▍Step 1
Go to THIS PAGE and tap the big red button indicated by a blue box.
▍Step 2
Fill in details as required.
▍Step 3
A verification code should be sent to your mail box after step 2. Fill in the code here.
▍Step 4
Fill in details as required.
▍Step 5
Double check that your info is correct.
▍Step 6
When you see this page, you are all set.