Downloading from Ryuugames typically involves a multi-step process that demands more from a user than standard storefronts like Steam. Tutorials generally emphasize three core pillars: Navigation and Link Decryption:

"Welcome back," Kenji smiled, the controller vibrating in his hands. The tutorial was over; the adventure had begun. technical steps

Change your system locale to Japanese (Settings → Time & Language → Language → Administrative Language Settings → Change system locale → Japanese). But Locale Emulator is cleaner.