Yo-kai Tribes

The are different groups that every species of Yo-kai is divided into. In battle, two or more adjacent Yo-kai in battle that hail from the same tribe receive a special Tribe Unity bonus, giving those Yo-kai a special boost to a stat that is best exemplified by that tribe.

The first Yo-kai Watch game introduced 8 tribes, with a 9th group called the Legendaries, though they are not a separate tribe in themselves, as those Yo-kai still belong to one of the eight Yo-kai tribes.

In Yo-kai Watch 2: Bony Spirits and Fleshy Souls, an official 9th Yo-kai tribe, the Wicked, was introduced, though it wasn't until Shin'uchi that the Wicked tribe Yo-kai could be usable in battle, and even then, only the Wicked executives and the Wicked-controlled Classic Yo-kai had a Yo-kai Medal to give.

In Yo-kai Watch Busters: Moon Rabbit Team, Lord Enma was introduced with a new tribe known as the Enma tribe.

In Yo-kai Watch 3: Sushi & Tempura, the existence of a eleventh Yo-kai tribe, the Hagure, was leaked via CoroCoro magazine following the finalist results of fans submitting their designs with the first (and only) Yo-kai being Android Yamada.