Many Japanese games have region locks.
To play those that are locked, a Japanese game console is required.
Many games can only be played in Japanese.
You need to check the language options in the game yourself.
This information should be readily available online.
Below is a list of all game consoles and whether they are region-locked or region-free:
●PS1 - Region Locked
●PS2 - Region Locked
●PS3 - Region Free
●PS4 - Region Free
●PS5 - Region Free
●N64 - Region Locked
●Gamecube - Region Locked
●Wii - Region Locked
●Wii U - Region Locked
●Nintendo Switch - Region Free
●Gameboy - Region Free
●Nintendo DS - Region Free
●Nintendo 3DS - Region Locked
●Sony PSP - Region Free
●Sony PS Vita - Region Free
●Sega Game Gear - Region Free
●PC Engine HuCard - Region Locked
●PC Engine CD - Region Free
●Sega Mega Drive - Region Free
●Sega Saturn - Region Locked
●Dreamcast - Region Locked
●Xbox - Region Locked
●Xbox 360 - Region Locked (some exceptions)
●Xbox One - Region Free
●Panasonic 3DO - Region Free (some exceptions)