Seems that the servers are down. Forever stuck at 12.50%. Waited for several minutes. Changed device language to japanese as well.
On their twitter they announced that the game will be terminated.
Proof:
Emulator, LDPlayer 9 Version 9.1.43.0(64), Android 9.0, rooted & patched with Magisk:
Emulator, Mumu Player 12 Version 3.8.18 ( 2845 ) Android 12.0, rooted & patched with Magisk: