What was the first Yo-kai Watch video game released in Japan?

The first Yo-kai Watch video game released in Japan was Yo-kai Watch. Developed and published by Level-5 for the Nintendo 3DS, it launched in Japan on July 11, 2013.

The game introduced the series' central premise: players choose Nathan Adams or Katie Forester, obtain the Yo-kai Watch, and use it to see, befriend, and battle supernatural creatures based on Japanese folklore. Whisper, a butler-like Yo-kai, guides the player after the protagonist encounters him.

Yo-kai Watch was announced at Level-5's 2011 Tokyo Game Show presentation, and its release became the foundation for a much larger multimedia franchise. The anime began in January 2014, and the game's popularity helped drive sales of toys, manga, and later games. A common mix-up is confusing this original title with Yo-kai Watch 2, which followed in Japan in 2014, or with Yo-kai Watch Blasters, a later spin-off.