Level-5 has announced a Japanese release date for Yo-kai Watch 4. The June date comes alongside a new trailer and a relaunch for the game's official website.
Yo-kai Watch Archives - RPGamer
Yo-kai Watch Jam: Yo-kai Academy Y Announced - RPGamer
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Everybody Plays in New Yo-kai Watch 4++ Trailer - RPGamer
Yo-kai Watch 4 - Japanese Version 1.3 Update Art and Screenshots - NintendObserver
Yo-kai Watch 4 Releasing in Japan in June; New Trailer, Details Released - RPGamer
Japan: Yo-Kai Watch 4 Will Release On The Nintendo Switch 6th June - My Nintendo News
Yo-kai Watch 4 - Wikipedia
Yo-kai Watch 4: latest trailer, official website update (+ 6th Yo-kai Watch movie announced) - Perfectly Nintendo