What was the initial launch platform for Yo-kai Watch 4?

Yo-kai Watch 4 initially launched on the Nintendo Switch. Level-5 developed the game specifically as a Switch entry, making it the first mainline Yo-kai Watch title to debut on that platform.

The Japanese release arrived on June 20, 2019, after an earlier planned 2018 launch was delayed. Unlike the preceding Yo-kai Watch games, which were associated primarily with Nintendo 3DS hardware, Yo-kai Watch 4 used a larger-scale action role-playing format and connected three different time periods in its story.

The main source of confusion is Yo-kai Watch 4++, an enhanced rerelease rather than the original launch version. That edition appeared later, on both Nintendo Switch and PlayStation 4, and added content such as a new map, enemies, and multiplayer features. Thus, the Switch is the correct answer for the initial platform, while PlayStation 4 belongs to the later 4++ release.