- Not to be confused with the video game of the same name in Japanese.
The Yo-kai Medallium (Japanese: 妖怪大辞典 Yōkai Dai-jiten) is a book that has small disc-shaped holes inside of it, which is where Yo-kai Medals can be stored. Each page has twelve slots for them, but some pages have them in an arranged order, which is where Legendary Yo-kai can be summoned by finding the specific medals.
Much like other related items, they come in different variants for different types of medals. While the main series games use the same red Medallium, the Yo-kai Watch anime series features the blue Medallium and the black-and-gold song Medallium.
They play a prominent role for collecting Yo-kai, being used as an item in the video games for keeping records of befriended Yo-kai and in Recap Time in the Yo-kai Watch anime.
It is a binder-like book that comes in different colors on the outside, with red being the most commonly-seen variant. There's also gold engraving on the front that has a symbol that resembles kanji writing, along with other undecipherable symbols on the top and bottom and symbols of each Yo-kai Tribe. The back has a diamond-shaped design with eyeshots of various Yo-kai on the sides.
They have been known to come in multiple colors, with slightly different front and back designs on each one such as the Tribe symbols being arranged in a different order. An example is the Song Medallium, which has music notes on the front. However, the Yo-kai Mystery File takes on a different appearance, looking more like a dossier than a mythical book.
Inside the Medallium are black pages that have twelve slots for Yo-kai Medals per page, along with the Yo-kai's name on the bottom-right of it. There's also two pages that have eight or six Medal slots arranged in a specific order that allows the user to summon a Legendary Yo-kai when all of their respective Medals have been collected.
In the games, the Yo-kai Medallium can be found in the player's room, on a rug near the bed, where it can function much like an Eyepo, allowing the player to switch out their Yo-kai Medals they have on hand.
The Medallium can be viewed in the Info tab in the Main Menu. It allows players to look at the bios of the Yo-kai they have befriended, as well as see the Yo-kai they have yet to befriend.
- The next pages after the collectible Yo-kai are the Boss Yo-kai pages, which shows the Boss Yo-kai the player has encountered and/or defeated. Players obtain these Yo-kai's bio by beating them.
- The last pages of the Yo-kai Medallium are known as the Legend Pages (Japanese: レジェンドページ Rejendo Pēji). These pages feature seals that require 8 specific Yo-kai Medals in order to break them. Once all of the Medals required for that particular seal are obtained, the player is then rewarded with unlocking a Legendary Yo-kai after interacting with the fully-weakened seal.
In the anime
It first makes an appearance in Yo-kai Medallium. After Nate is intimidated by his mother for not cleaning his bedroom, he has trouble deciding where to place the Yo-kai Medals he has collected. Whisper gives the Yo-kai Medallium to Nate.
It reappears in The Legend of Shogunyan, where Nate manages to collect several Yo-kai in order to summon Shogunyan. After it plays the summoning chant, Jibanyan decides to take a nap inside Nate's closet only for Shogunyan to emerge from it.
It reappears in The Legend of Dandoodle, where Nate has filled up the Yo-kai Medallium with all of the Yo-kai he has befriended. Whisper coughs up a blue Medallium, which Nate finds gross and cleans it up for it to be used.
The Yo-kai Medallium is also featured in Recap Time.
- Main article: Yo-kai Medallium (merchandise)
The Yo-kai Medallium has been made as a collectable binder for real life Yo-kai Medals, that almost mimics the usage of the Medallium in the games and anime.
Unlike the original thing, Medallium pages have been made for Japanese and western merchandise.
- In the first game, Gilgaros' Legend Page is the fifth/final one. This is moved to its correct spot as the third Legend Page in the second game.
- There is a Yo-kai based on the Medallium called Yoderusen.