The Yo-kai Watch (Japanese: 妖怪ウォッチ Yōkai Wotchi) is the titular device which the series revolves on. It is a special watch that allows humans to see and communicate with Yo-kai. Yo-kai also use it to communicate with humans.
The Yo-kai Watch is an unique piece of technology which helps humans to uncover and communicate with Yo-kai, a feat normally impossible without the use of this device. Conversely, the Yo-kai watch is useful for Yo-kai to communicate with humans.
The real power of the Yo-kai Watch, however is the ability granted to the use to summon Yo-kai he/she has previously befriended by inserting their respective Yo-kai Medals into its gap. Each of the eight primary tribes of Yo-kai have their own summoning song, as well as their surge of light sporting the respective color of the backs of their medals. It should be noted that a medal inserted upside down (or wrong side up) will not trigger the summon; the original Watch model had it where it would make the leader of the Nosirs say: "Ah ah ah!" in a scolding manner.
Similarly, the user who wears the Yo-kai Watch is the only one who can summon Yo-kai. Likewise, Yo-kai themselves who are being called can deny the summon, and may bring other Yo-Kai with them (as shown in episode 56 when Komajiro joined Komasan for a summoning).
Yo-kai Watch 1 & 2
The Yo-kai Watch, in its Model Zero incarnation, was first conceived by Nathaniel/Kenny around 60 years ago. Nathaniel/Kenny also created Yo-kai Medal prototypes for five of his closest Yo-kai friends, which were Classic Yo-kai.
In the present day, on one summer day while trying to catch bugs for a summer project, Nate/Katie (depending on which character the player is using) receive a present-day model of the Yo-kai Watch (which also differs depending on the character) courtesy of a freed Whisper, who instructs he/she to use its light to uncover Buhu in order to start a combat, which began a series of misadventures that lead to the discovery of a diabolical plot. After the player defeats the would-be usurper McKraken, the Yo-kai Watch fades along with the Yo-kai out of the character's sight as the seal transports all Yo-kai back into the Yo-kai World, though the Yo-kai Watch and all Yo-kai eventually return.
However, one night, Kin and Gin (with Bronzlow appearing as well in Shin'uchi) arrive over Nate/Katie's house while they were sleeping and caused the Yo-kai Watch along with it's owner's memories to vanish. The next day, Nate/Katie finds the Yo-kai Watch in the Memory Shop. The shop owner offers he/she to sell the Watch for just $1.00 (¥100 in Japan), then to use it at the Crank-a-kai outside. Nate/Katie buys one of the capsules and drops it aside, revealing Whisper. The Yo-kai Watch restores the memories of both Nate/Katie and Whisper, among them ones about Jibanyan. When Nate/Katie and Whisper reunite with Jibanyan, the Yo-kai Watch restores Jibanyan's memories as well.
After traveling 60 years into the past, Nate/Katie learns from Hovernyan about the Yo-kai Watch Model Zero. Whisper then explains the normal model was created by Steve Jaws. Sometime later, Nate/Katie gives Nathaniel/Kenny the main piece needed to finish the Yo-kai Watch Model Zero. Nathaniel/Kenny then entrusts Nate/Katie with the watch.
Yo-kai Watch 3
When his mother got inspirited by Cornfused after Nate finds her misplaced glasses, he discovers that his Yo-kai Watch can't make Merican Yo-kai appear when hit by the light. Moping at the failure in his room, Whisper soon gives him the Yo-kai Watch U-1 to replace the Yo-kai Watch and allow him to see Merican Yo-kai. Inaho later obtains her Yo-kai Watch U-2 in the same manner she did in the anime, where it was through USApyon's machinations that she got it outside the store, as the barcode on the box was illegitimate.
Steve Jaws came to Nate's rescue after losing to Ma Injaneno. Nate got the Yo-kai Watch Dream and defeated him.
Mark Shachiberg later invites Nate, Inaho, and several Yo-kai to his building, where all of the Yo-kai Watch models have been gathered and put on display. At the end of the chapter, Inaho gets her own Yo-kai Watch Dream.
During a mission in a cowboy town, Nate temporarily lends his Watch to a local so that she can see a Yo-kai, and she returns the watch to him shortly afterwards.
The circumstances that lead Nate into obtaining the Yo-kai Watch in the anime are fairly different. In Yo-kai Are Real!, Nate returns to his house with Whisper and he finds his parents arguing. Because of that, Whisper notes that's "her" doing. After Nate wonders what is he talking about, Whisper gives him the Yo-kai Watch and instructs him to shine its light onto his parents; Nate finds Dismarelda this way.
In The New Yo-kai Watch, Whisper and Nate witness Yopple CEO Steve Jaws' conference about the new Yo-kai Watch Model Zero through Whisper's Yo-kai Pad, explaining that he was able to mass-produce it with new technology, then announcing its release on the same day of the presentation. After acquiring the new model, Nate tries to use it and learns he must use Z Medals to get it to work. Afterwards, Jibanyan gives Nate his three new medals and Nate finally uses it successfully. Accidentally, the Yo-kai Watch Model Zero ends inside Whisper's mouth, and Nate discovers he can switch between watch models by diving his hand into Whisper's mouth.
In EP077, Inaho finds a Yo-kai Watch U, labelled as a "Space Watch" in an anime store thanks to a "faint voice" and decides to buy it. Sometime later and believing it was a fake, she lights an unknown Yo-kai using its light during class, sparking a new interest on the watch. At home, using the watch, she finds USApyon, who tells her about the Yo-kai Watch U and gives his Yo-kai Medal to test it.
In EP078, following the announcement of Steve Jaws' stepping down from Yopple, the newly appointed CEO Mark Shachiberg unveils the Yo-kai Watch U and describes some of its features before ending his exposition saying it was just a prototype and it was handed to notable people in the Yo-kai World only, which distraughts Whisper, who set himself into going to purchase it. However, Hidabat emerges from Nate's closet with one of the prototypes, which she got thanks to her friendship with Shachiberg, as evidenced by a photo taken on Nate's room, and offers it to Nate, as the bat Yo-kai cannot use it. Nate tests his new watch with Jibanyan's old medal successfully, but expresses some lack of interests about its other features due to Pintocorn possessing him.
In EP098, the two Watches get upgraded. Nate's watch becomes the light-blue Yo-kai Watch U-1 while Inaho's watch becomes the yellow Yo-kai Watch U-2.
In EP130, Tomnyan informs Nate, Whisper and Jibanyan of the Yo-kai Watch Dream, and the four of them, along with Hidabat went to Dream Land and attempted to get it via the Roulette Machine; however, Jibanyan and Tomnyan are unsuccessful as well as Whisper, who now is missing his head swirl, his tail, the black strip between his eyes and his lips, as he had to barter parts of his body in lieu of not having a Yo-kai Medal. Whisper ended up getting the Yo-kai Watch Dream from Walkappa, via trading with other Yo-kai that were there.
|Yo-kai Watch (Japanese: 妖怪ウォッチ Yōkai Wotchi)|
| This Yo-kai Watch model is the most often-seen variant. It allows the user to summon Yo-kai which have silver medals, and the golden-framed Medals of the first five Legendary Yo-kai (Shogunyan, Dandoodle, Elder Bloom, Komashura, and Gilgaros). Whenever a Yo-kai Medal is inserted into the Yo-kai Watch, it plays a special tribe-specific summoning song.
If Katie is chosen as the player character in the games, in EP067 as well in the manga, her Yo-kai Watch model looks noticeably different: it is designed in the grounds of a Pocket Watch, complete with a strap, emblazoned with heart patterns. Despite its appearance, it has the same functions and features as the regular model.
Curiously, in the variant cover for the second issue of the Yo-Kai Watch IDW comic, Katie is shown with the same version of the watch as Nate. 
| Yo-kai Watch Model Zero (Japanese: 妖怪ウォッチタイプ|
This model was conceived/invented by Nathaniel/Kenny 60 years ago, making it the very first usage of a Yo-kai Watch. In the anime, this model was mass-produced by Steve Jaws.
It allows the user to summon present day Yo-kai that have Z-Medals (which have green frames), Classic Yo-kai which have Classic Medals (with dull red frames), the remaining Legendary Yo-kai Spoilerina, Poofessor, and Slurpent) and the Wicked Yo-kai. Yo-kai not belonged in said groups cannot be summoned; however, they can update their medals (as seen with Jibanyan) to allow their summoning. Barring the Wicked tribe, none of the summoning songs have lyrics; instead using instrumental variants.
To trigger the summon, the user must insert the medal, turn the arrow to "1" to play the summoning song, and finally drag it to "2" in order to call the Yo-kai.
When using the Yo-kai revealing light on this model, it gives off a short announcement before allowing the user to use the light.
For some reason, Nate never uses this watch to find Yo-kai in the anime.
| Yo-kai Watch U (Japanese: 妖怪ウォッチ|
This model was conceived and developed by Mark Shachiberg.
It has absolute backwards compatibility with previous medal types, allowing it to use present, Z, and Classic Medals, as well as being able to summon Present Yo-kai with U-medals -designed specifically for use in this model- and Merican Medals. Each summon begins with a Yo-kai announcer saying "Ladies and Gentlemen", then stating the tribe of the Yo-kai being summoned. Summoning songs are different from previous models, and each feature a small Yo-kai chorus in a different background, similar to a performing stage. Likewise, Song Medals can be used in this model, each featuring an extended version of the summoning song -for solo Yo-kai- and a radically different song -for Yo-kai Units-.
According to Shachiberg, this model has the potential to continue evolving, as hinted by a small slot on the left side of the watch.
| In EP098, Mark Shachiberg announces an update to the U model. This update allows the Yo-kai Watch to summon Great Legendary Yo-kai, as seen with Edison. Completing the update allows the Yo-kai Watch U to reach its perfect form. There are at least five color schemes to choose from, even though two of them are used. Nate chooses the light-blue U-1 color (left) and Inaho chooses the yellow U-2 color (right).
In the video games, both Nate and Inaho start out with the U1/U2 models of the Yo-kai Watch U, in a similar way how they had gotten their Yo-kai Watch U Prototypes in the anime, though Nate had retrieved his soon after settling into his new home in St. Peanutsburg.
| During the events of the second movie, Nate attempts to summon Lord Enma with his U-1, but he fails. However, his watch carried some power to Inaho's U-2 and both Yo-kai Watches temporarily assume the Yo-kai Watch U - Version E (Japanese: 妖怪ウォッチ|
|Yo-kai Watch Dream (Japanese: 妖怪ウォッチドリーム Yōkai Wotchi Dorīmu)|
| The Yo-kai Watch Dream was developed by Steve Jaws in exile after stepping down of Yopple and Mark Shachiberg took his place.
In EP130, Nate, Whisper, Jibanyan, Hidabat, and Tomnyan visited Dream Land to participate in a roulette game to win various prizes, including the Yo-kai Watch Dream, which they had arrived to obtain. Because of their poor luck, Whisper trades off his body parts for tokens since he doesn't have a Yo-kai Medal. He doesn't outright win the watch yet manages to obtain it by trading off the items he did get.
Like the Yo-kai Watch U, all Yo-kai Medals can be inserted into the watch and summoned correctly, and has a series of Medals, the Dream Medals, that will work solely with the Yo-kai Watch Dream. When a Yo-kai Medal is inserted into the watch, the Watch announces "It's a (tribe name) time! (Event/food) Roulette!" as the bulbs on the watch light up, then put that Yo-kai through a challenge of luck that determines how they feel when they are summoned; unavoidably due to this gimmick, this Watch model sometimes causes problems for the Yo-kai who is summoned. When they win, they get a giant victorious fanfare with cheering in the background, while when they lose they get a lose fanfare and a chorus reciting what they did get instead with some samba music, then with a final fanfare, the Watch plays a laugh track at the Yo-kai's misery.
The Yo-kai Watch Dream is powerful enough to summon Lord Enma without assistance, as shown in EP138 when Nate summons Lord Enma solo style to battle Gachin-kozo implying that this is the strongest Yo-kai Watch.
The 7 types of Roulettes are Sushi (Japanese: 寿司ネタルーレット Sushi-neta Rūretto), Dream (Japanese: ドリームルーレット Dorīmu Rūretto), Shopping Mall Lottery (Japanese: 商店街福引きルーレット Shōten-gai Fukubiki Rūretto), Tempura (Japanese: 天ぷらルーレット Tenpura Rūretto), Vending Machine (Japanese: 自動販売機ルーレット Jidō Hanbaiki Rūretto), Christmas Present (Japanese: クリスマスプレゼントルーレット Kurisumasu Puresento Rūretto), and Seat Changing (Japanese: 席替えルーレット Sekigae Rūretto).
The biggest departure from typical Yo-kai Watches, however, is the fact that the Yo-kai Watch Dream has special gear that is designed to work with it via a function called Dream Link, and as such, can be detached from its base. It is compatible with the Yo-kai Blaster (Japanese: 妖怪ブラスター Yōkai Burasutā), a gun-like weapon the Watch wearer can use to do additional damage to their Yo-kai opponents, the Yo-kai Bazooka, the Yo-kai Drill (Japanese: 妖怪ドリル Yōkai Doriru), a excavation drill used to destroy impeding rock, and the Yo-kai Cleaner (Japanese: 妖怪クリーナー Yōkai Kurīnā), a UFO-like device that gathers items that increases in power by leveling up.
It is currently unknown if Inaho will get this watch in the anime like she did in the video game.
|Black Yo-kai Watch (Japanese: 黒い妖怪ウォッチ Kuroi Yōkai Wotchi)|
|This model seems to only appear in an alternate world -known as the Dark World-. Its creator is unknown.
This model is unique in that instead of searching for Yo-kai, its light -purple in color- scans a human and causes a being sealed in the watch to swallow the human whole, after that it spits him/her out transformed into a Yo-kai -as seen with Kemushi-otoko, Mukade-otoko, Hae-otoko and Kamakiri-onna (Nate, Bear, Eddie, and Katie respectively).
In Real Life
Following their appearances in the anime, real-life replicas of the various models of the Yo-kai Watch are being released in Japan, each with two Yo-kai Medal replicas. More medals can be obtained by buying them in packs or by the Gashapon.
|Released on January 11, 2014 in Japan with Yo-kai Medals of Jibanyan and Dismarelda.|
|Released on August 2, 2014 in Japan, with Yo-kai Medals of Jibanyan (Nyext Z Medal) and K'mon-K'mon.|
|Released on April 25, 2015 in Japan, with Yo-kai Medals of Goldenyan and Baddinyan.|
|Released on August 1, 2015, with Yo-kai Medals of USApyon and Cornfused.|
|Released on July 30, 2016, with a Dream Medal of Jibanyan and a normal Robonyan USA Medal.|
|Released on February 18, 2017, with a Black Jibanyan and a Kemushi-otoko Medal.|
Upgrade Kits & Accessories
|Released on December 12, 2015 in Japan as part of the Evolution Kit series, with Yo-kai Medals of "Nyanyan All Stars" and Edison.|
|Released in December 12, 2015 as part of the Evolution Kit series, with Yo-kai Medals of "Amekome Club" and Edison once again.|
|Released in December 26, 2015 as part of the Evolution Kit series, with Yo-kai Medals "Red Hot Oni Backers" and Lord Enma (Pre-Awakening).|
|Released in October 22, 2016 as a separate accessory for the Dream Watch. Comes with a Tengu Dream Medal.|
|Released on November 14, 2016 as a separate accessory for the Dream Watch. Comes with an Ultimate Robonyan Dream Medal.|
|Released in November 23, 2016 as a separate accessory for the Dream Watch. Comes with a Lord Enma Dream Medal.|
|Released on March 25, 2017, with a Treasure Jibanyan (Dream) Medal.|
North America & Europe
|Released on December 28th, 2015 in America with Yo-kai Medals of Jibanyan and Whisper. This watch is not compatible with even Jibanyan's Nyext, Nyaight, and Victory pose Z Medals like the Japanese one technically did.|
|Released on October 1, 2016, with Yo-kai Medals of Jibanyan (Victory Pose Z Medal) and K'mon-K'mon. Unlike the Japanese counterpart and like the Yo-Kai Watch U, this watch is also 95% compatible with all normal medals. This watch also has Yo-Motion that displays the Yo-kai corresponding to the medal.|
- The Yo-kai Watch U is the sole Yo-kai Watch model that had multiple versions, with six: the U-1, U-2, U-3, U-4, U-5, and the Version E. However, only the U-1, U-2, and Version E models were made into toys. The unused Yo-kai Watch U models are the green U-3, the violet purple U-4, and the pink U-5.