Touma Shinya has always been indifferent toward the Christmas holiday nor does he believe that Santa exists for the past ten years. However, his resolution is put to the test when he notices a strange girl trying to find the mother of a lost child. Because he witnessed her magically henshin into a Santa outfit plus give an early present in an attempt to cheer the child up, he is now a potentially dangerous target to Santa society. Luckily for him, he manages to escape her terrifying wrath with his speedy legs.

Later while visiting his neighbors, the Seiya’s, he recounts his experience and to his surprise, they were taking his ludicrous-sounding story seriously. It was at that moment when the crazy Santa girl enters through the window and demands to know why the Seiya’s were not delivering gifts to children as they were assigned to do. Because of their actions, the “snow of happiness” has not fallen for over ten years. Shinya now realizes with great disbelief that his neighbors are Santa’s as well. And so marks the beginning of a skeptic becoming a “Santa’s helper” for the goal of spreading the Christmas cheer.

[From a blog post by M3rryweather]