The story takes place in the dark and gray Halloween town, where various ghosts live, their only task is to prepare for the annual Halloween. The tall and thin skeleton man, Pumpkin King Jack, is deeply loved by monsters, but no one knows his inner pain. He has poetic melancholy and romantic feelings, longing for a life different from the evil in Wansheng Village.
When Jack accidentally found some big trees in the depths of the woods, strange doors were carved on the trunks. He was fascinated by one of the doors carved with Christmas trees. Under curiosity, he opened the magic door, and suddenly fell into another world of white ice and snow—Christmas Town, with the bright lights of the town. The colorful colors amazed Jack, and the joyful atmosphere in the town made Jack even more fascinated. In order to appreciate Christmas, he kidnapped Santa Claus and produced "presents" according to Christmas rules.
Jack has a good wish-to bring joy to people, but his monsters will only produce all kinds of scary toys. They wholeheartedly think this is another "holistic plan" devised by the great Jack. So Christmas turned into Halloween, and people woke up from the screams of children. They bombarded Jack, who was wearing Santa Claus clothes and was driving a deer cart across the sky with joy.
In the end, Jack realized his mistake and rescued Santa Claus from the monster Ukibuki, letting Santa bring people a happy Christmas again to save his mistake. At the same time, he also found a confidante who understood him-Miss Doll Sally.
