On a certain riverside, there lived three yōkai: Azuki-Arai, Azuki-Hakari, and Azuki-Babaa. Modern people, who have never even touched an azuki bean, pay no attention to them. Nezumi-Otoko happens to pass by the troubled trio who want to suppress western confectionery and restore the azuki beans to their former glory. Nezumi-Otoko comes up with yet another money-making idea: he tells the trio that they can make azuki beans popular again, but they first need to become famous enough to be advertising pillars. As the producer, he becomes delighted when their silly videos become very popular. However, the three get into an argument about the true way to show their love for azuki beans, and their Azuki Union fellowship begins to crack!