"A grand journey that goes beyond the time and space of the world in which Natsume, Nate, and Shin live in".
Around the end of May 2017, series creator Akihiro Hino wanted to "refresh the series" due to the decline in sales of Yo-kai Watch 3, compared to Yo-kai Watch 2. He also stated that a "new flow" would begin with the fourth movie, which would win back older fans of the franchise.
Details on the fourth mainline game were finally revealed in April 2018, with is set to be released around Winter 2018 on the Nintendo Switch with a Winter 2018 release date. It will feature characters from the Shadowside series and will feature an upgrade that will surprise the players.
More details on the game were also revealed in the monthly CoroCoro magazines that revealed 7 new Yo-kai Tribes for Yo-kai Watch 4. The new tribes are listed as Goriki (tribe), Onnen (tribe), Mononoke (tribe), Tsukumono (tribe), Uwanosora (tribe), Omamori (tribe), and Mikakunin (tribe).
The first teaser for the game was released on June 23, 2018. It also revealed that the game will feature a young Nate in his Yo-kai Watch 3 outfit, along with Whisper, and Jibanyan in their original designs. The teaser also featured new characters Shin Shimomachi, and Nekomata who are set to appear in the fifth movie Yo-kai Watch Forever Friends. They all are shown to enter the setting of the game through certain doors opened by Natsume.
On October 10, 2018, Level-5 had annouced that Yo-kai Watch 4 will be delayed into 2019 spring with no slated release date. No official reasons have been given for this delay.
- This will be the very first mainline Yo-kai Watch game to:
- Be released on a home console, rather than the handheld console.
- Be played in a third-person view, much like what was shown in the 2011 trailer for Yo-kai Watch.
- Be able to "jump" in the air to reach high areas.
- To switch between more than two protagonists.
- Have a battling mechanic similar to the Blasters side games.
- To have normal befriendable Shadowside Yo-kai be Bosses.
- Have a main game other than sidequests bring back old bosses.
- First main game in the series to feature Kuroi Yo-kai in the game.
- First game to use humans in battle.
- This is also the first game since Yo-kai Sangokushi that isn't split into two versions (discluding the North American/European version of Yo-kai Watch 3).
- This will be the second game to be released on a console, the first being Yo-kai Watch Dance: Just Dance Special Version.
- A keychain of the game's box art was given out at World Hobby Fair 2019, but it is currently unknown whether or not it is the final box art.