Watcher

Nathan "Nate" Adams
Nathan Adams                                                                                                                                                  Yo-Kai Partner: Jibanyan                                                                                                                                   Current Yo-Kai Watch: Yo-Kai Watch Dream Model (since EP130)                                                                      Former Yo-Kai Watches: Original Yo-Kai Watch (1-78), Yo-Kai Watch Model Zero (27-78), Yo-Kai Watch U Prototype (78-98), Yo-Kai Watch U-1 (98-130).

Obviously having a Yo-Kai Watch from EP001, Nate usually is the one who comes across the Yo-Kai and tries to befriend them with help of his Yo-Kai friends and it led to him having currently 5 watches. The first one was used from EP001 which uses only Normal Yo-Kai Medals it was used until EP078 after he got the Yo-Kai Watch U Prototype, although it did reappear into the series starting with EP131 when its revealed Jerry has a Yo-Kai Watch like Nate's first watch even though Jerry uses it wrong.

Later Nate got the Yo-Kai Watch Model Zero in EP027 which only uses Z Medals and Classic Medals leading Nate to switch between his first 2 watches depending on what kind of Medal he is using, like the Original Yo-Kai Watch it was used until EP078 after he got the Yo-Kai Watch U Prototype.

Then in EP078 Nate gets the Yo-Kai Watch U Prototype from Hidabat after it is revealed that Hidabat is a good friend of the CEO of Yopple Mark Orckerberg and received one from him, this watch uses all the past medals from the previous 2 watches along with U Medals and 'Merican Medals, 20 episodes later in EP098 Nate's U Prototype was upgraded to the Yo-Kai Watch U-1 which added the Great Legendary Yo-kai and the watch having a new color scheme Nate's being light-blue, it was used until EP130 after Nate got the Yo-Kai Watch Dream Model.

In EP130 Nate and the gang travel to Dream Land to participate in a roulette to win the Yo-Kai Watch Dream Model, Nate later receives it after Whisper got it in a trade. The Yo-Kai Watch Dream Model can use all previous medals and Dream Medals. The Yo-Kai Watch Dream Model acts as a roulette when summoning a Yo-Kai either winning or losing, this watch also adds the function known as Dream Link where the Dream Model's body can attach to special weapons used for such as to attack, destroy stuff, and gathering items. This is Nate's current watch.

Hailey Anne/Inaho Misora
Hailey Anne                                                                                                                                                       Yo-Kai Partner: Usapyon                                                                                                                                 Current Yo-Kai Watch: Yo-Kai Watch U-2 (since EP098)                                                                                   Former Yo-Kai Watch: Yo-Kai Watch U Prototype (77-98)

Hailey first appeared in EP077 after she didn't get the Limited Edition Sailor Piers Figure which sold out she finds a Yo-Kai Watch U Prototype titled a "Space Watch" and buys it where later after figuring out how it works she meets Usapyon. Unlike Nate she is usually seen in segments or something that doesn't involve encountering Yo-Kai causing trouble and because of that she has never really used her watch for summoning. Like Nate's U Watches, it uses all previous medals before the U Watch along with the U Medals and 'Merican Medals. In EP098 Hailey's U Prototype was upgraded to the Yo-Kai Watch U-2 which added the Great Legendary Yo-kai and the watch having a new color scheme Hailey's being yellow. The U-2 is Hailey's current watch.

Jerry
Jerry                                                                                                                                                                  Yo-Kai Partner: Tomnyan                                                                                                                                   Current Yo-Kai Watch: Original Yo-Kai Watch (since EP131)

Jerry first appeared in EP131 after moving next door from Nate's House and its revealed that Jerry has a Yo-Kai Watch like the first one Nate got and Tomnyan is his partner. Jerry calls the Yo-Kai Watch the "Sojanaiyo Watch" since that is all he does with the watch since he doesn't know how to properly use it and he always does something wrong though usually he puts in a 'Merican or Dream Medal in with its back side facing up since his watch only uses Normal Medals and the medal is put in wrong.

Katie Forester
Katie Forester                                                                                                                                                  Yo-Kai Partner: Baddinyan                                                                                                                                Yo-Kai Watch: Katie's Yo-Kai Watch/Original Yo-Kai Watch (only in EP067)

In a dream of Whisper in EP067 he was the Yo-Kai Butler of Katie, who had her own version of the Yo-Kai Watch where it was a pink watch that went around her neck, and instead of Jibanyan, her partner was Baddinyan and instead of Hidabat in the closet it was Shadow Venoct. just like the Original Yo-Kai Watch it only uses Normal Medals. Though excluding the games and manga, EP067 is the only episode to feature Katie as a Yo-Kai Watch User.

Nathaniel Adams
Nathaniel Adams                                                                                                                                               Yo-Kai Partner: Hovernyan                                                                                                                                Yo-Kai Watch: Yo-Kai Watch Model Zero (only in M01)

After receiving the Model Zero and the medals of the Yo-Kai he saved in M01, Nathaniel used the watch to summon all the Yo-Kai he has saved. He later gave the Model Zero to Nate before Nate went back to his own time.

Yuto Arima
Yuto Arima                                                                                                                                                         Yo-Kai Partner: Fuu2                                                                                                                                         Yo-Kai Watch: Yo-Kai Watch U-1 (Only in M02)

During the events of Nate being turned into a Yo-Kai in M02 for the 1st out of the 5 episodes of the movie, Nate also known as Fuu2 comes across Yuto who apparently got an average grade on his test because of Fuu2, Fuu2 eventually gives Yuto the Yo-Kai Watch Fuu2 got when becoming a Yo-Kai which was the Yo-Kai Watch U-1. Yuto never used it for summoning since he never befriended any Yo-Kai besides Fuu2 and Fuu2 was always with him, though he has used it for finding Fuu2. After Yuto realized that his parents will support him for whatever career he goes for (in his case writing manga) and that he has something to live for, Fuu2/Nate becomes his average human self again. It is unknown what happened to his watch after Fuu2 left.

Black Jibanyan
Black Jibanyan                                                                                                                                                   Yo-Kai Partner/Yo-Kai Watch: Black Yo-kai Watch (156, 158-163)

Black Jibanyan and the Black Yo-Kai Watch take place in an alternate world where Dark versions of Jibanyan and Komasan go after humans and turn them into Yo-Kai with a talking Black Yo-Kai Watch (and sometimes find other Dark Yo-Kai). During the Black Yo-Kai Watch miniseries Black Jibanyan and Komasan use the Black Yo-Kai Watch which is actually a Yo-Kai itself to turn humans into Yo-Kai such as seen with Nate being turned into Kemushi-otoko. This watch can uses Dark Yo-Kai Medals including all the medals from the past.

Natsume Amano
Natsume Amano                                                                                                                                                Yo-Kai Partner: Jibanyan (M04)                                                                                                                          Yo-Kai Watch: Yo-Kai Watch Elder (M04)

Natsume who is Nate's daughter in the future received the Yo-Kai Watch Elder from Whisper who safely guarded it for 30 years until he gave it to Natsume. This is a unique model of the Yo-kai Watch developed 30 years after the anime. This model of the watch resemble that of the original Yo-Kai Watch worn by Natsume's father, Nate. It is white in color all over, and has two hinges on each side. The inside has a working mechanical detail, which only can be seen if the watch is opened. Unlike the previous watches, the Yo-kai Watch Elder uses Key-shaped medals, used to summon Yo-Kai and also allows them to shift through either Lightside or Shadowside forms.

Touma Tsukinami
Touma Tsukinami                                                                                                                                              Yo-Kai Watch: Yo-Kai Watch Ogre (M04)

This unique Yo-kai Watch created from the remains of the Kigan Gear after Touma found his own resolve against the Onimaro's influence. Unlike any models of the watch, the Ogre doesn't rely on using medals at all. Instead, it allows the user to summon only 4 chosen Yo-Kai from the watch by pressing the button on the side and rotating the dial to the specific spot. Pushing the center of the watch down would allow it to summon the chosen Yo-Kai in battle. Also, if the Fudou Raimeiken is inserted into the watch, it can summon Fudou Myouou in battle.