Master Oden resembles a Signiton that is clad in clothes befitting an oden stew vendor, with his horns replaced with oden skewers, and wields a ladle.
Master Oden appears to enjoy listening to heartwarming stories and tearjerkers, to the point where he prevents people from eating until he's heard a satisfying tale. According to him, only a sufficiently heartwarming story can allow the broth to reach its highest depth of flavor.
Anyone Inspirited by Master Oden becomes compelled to pour their heart out and share their worries and grievances, often in the form of a song or dramatic performance. They also share his personality and adamantly refuse to eat any oden stew being served until a touching story has been told.
In the anime, Master Oden can manifest a bar meter that fills up based on how heartwarming a story is. He relinquishes his Inspiriting when the meter fills up completely.
Yo-kai Watch animation series
Master Oden appears in EP059, Inspiriting Lily and Aaron before dinner. This causes them to tell stories about their daily hardships and refuse to let Nate eat his oden. Nate reveals Master Oden, who explains that he will only let everyone eat once he hears a satisfying story. Jibanyan and Whisper fail miserably in their attempts, and even Komasan's story about how he and his brother Komajiro took care of each other when they fell ill fails to convince Master Oden completely.
Nate finally summons Hungramps, who tells them the story of his final moments and how his granddaughter was inspired by her love for him to become a doctor. This tale moves everyone to tears, including Master Oden, who allows the meal to commence and gives up his Yo-kai Medal.
Complete the Oden of the Soul Request series, and Master Oden will join automatically.
As for Master Oden's locations, he doesn't have any strict locations, for he shows up in random location all over Springdale during clear nights. Since he moves with each clear night, the player must prepare beforehand for the sake of convenience:
Odenjin is a pun off his color palette swap Signiton (Japanese: でんじん,Denjin), and oden, a Japanese winter soup.
"Don Kaldo" is a corruption of "Don Caldo" (Don Broth).
Master Oden appears to be partially based after an oden cart vendor. Similar to the one who befriends Manjimutt in the show, oden stew vendors can be seen in Japan, hawking their wares from carts set up at night. They colloquially listen to the woes and backstories of their customers.
Master Oden's "random" names are: Dennis, Kumquat, Chef, and Stu.