Kibidango emerges as a small, blue, dog-like creature who slips into Mario and Luigi's grocery store. He spots and snatches Princess Peach's forgotten emerald brooch, sparking the brothers' pursuit into the Mushroom Kingdom.

Inside the Mushroom Kingdom, Kibidango reluctantly guides Mario and Luigi during their mission to save Princess Peach, obeying the elderly hermit Kinoko Sennin. He remains alongside them for the entire journey, communicating mostly through barks and showing minimal initiative when confronting challenges.

After Bowser's defeat, Kibidango's true identity surfaces. He transforms into Prince Haru, ruler of Flower-koku (Flower Kingdom), when Mario returns Peach's brooch and shatters Bowser's curse. Prince Haru discloses that Bowser cursed him into canine form to sabotage his prearranged marriage to Princess Peach before her capture. This confirms his role as Peach's fiancé, clashing directly with Mario's romantic hopes.

Kibidango operates chiefly as a plot mechanism. His brooch theft launches the adventure, while his unmasking reshapes the rescue's context. As a canon addition to Mario lore absent from games, he forges a unique conclusion where Mario and Peach lack a romantic bond. His blue canine design echoes later Wiggler enemies, and his Flower Kingdom ties mirror *Super Mario Bros. Wonder*'s setting, though no franchise continuity links them.

Kibidango's background receives no expansion beyond his curse and royalty. He features in no other media.