Daily Yo-kai Watch Factsさんのイラストまとめ

The Yo-kai Medallium states that Komashura is a "legendary Komasan with the heart of a greater demon". This implies the existence of multiple Komasans, although how one of them turns into Komashura is never further explained.

Lord Enma can be seen shooting down plushes of Jinpei, Sandayu, and Mera, who are sporting their appearance from Y School Heroes: Gag Side Stories in Chapter 8 of the Enma's Holiday manga.

Snake King Army Yo-kai from Yo-kai Watch Puni Puni's third shogi event all have the common characteristic of wearing bead necklaces.

Yo-kai Watch 4++'s opening has a texture error on Lightside Shogunyan's helmet, where its emblem is green, red, blue, purple, and black, as opposed to its usual gold.

Sgt. Burly is based off of American martial artist, Billy Blanks.

Nate's mother, Lily Adams, is seen without her signature orange tie in Yo-kai Watch 4.

Metsuryutai Jibanyan's artwork is traced directly from Momonyan's artwork.

According to Ultimate Robonyan's Inspirit Card Battle Card and special figure set, his form where he turns into a missile pod is called "Ultimate Robonyan (Saishuukeitai)", saishuukeitai meaning "final form" in Japanese.

Rubeus J can be seen in the background of Venoct's Bandai Z Medal, referencing his arc in the Yo-kai Watch anime: "Venoct's Revenge: The Search".