Whilst shopping for some flowers in her local market, Tamako Kitashirakawa, the daughter of a mochi shop owner, encounters a peculiar talking bird named Dela Mochimazzi that decides to follow her home. As Tamako and her younger sister Anko go to the public baths later that evening, Dela has Tamako's childhood friend, Mochizō Ōji, take him to the baths as well. As New Year's Eve arrives, with Dela having put on weight after gaining an affection for mochi, Dela almost chokes on a mochi, prompting the neighbourhood to help him out, overlooking Tamako's birthday.

As Valentine's Day approaches, Tamako suggests the shopping district should hold a Valentine campaign. However, Tamako's father, Mamedai, is against the campaign, believing it to be too modernised. As Tamako and Mochizō start shooting a commercial for the shopping district, Tamako's friend, Midori Tokiwa, feels conflicted by feelings she starts having around Tamako. At the screening of the commercial, Dela manages to stand in for the projector by projecting the image through his eyes. When the commercial finishes, Dela shows another video, this time a video message from his home country. As Valentine's Day arrives, Midori comes to terms a little with her feelings.

As the whole shopping district takes an interest in Mechya, Tamako feels a little confused by everything, the empty shopping district begins to remind her of when her mother died. When asked by Dera about what she thinks of the whole bride business, Tamako talks about how much the district has meant to her over the years. Tamako rushes to turn down Mechya's proposal, only to learn that she isn't actually a candidate, as Choi has misunderstood things. After the girls see them off, Choi and Mechya head back to their home country, only to realise they've left Dera behind. Come New Year's, Dera attempts to head back home by hiding himself in a bouquet, only to wind up in a box Mochizō has ordered for Tamako's birthday and end up right back on Tamako's doorstep.