A special episode listed as 5.5 on bilibili.

Winter was once the only season in the world-but such an existence was too lonely to bear, and so it created Spring to love. Before long, the earth wished for more time to rest in the cycle, and Summer and Autumn were born. The ones who carry the cycle are called the Agents of the Four Seasons. Hinagiku, the Agent of Spring, disappeared from this land ten years ago, taking the season of spring with her. Now, after incredible hardship, she has returned to restore the cycle to its proper state-and, as in the myth passed down since the dawn of time, she sends her love to Winter.

Lupin III and his friends head for the Bermuda Sea, aiming for a "mysterious island" that does not exist on the world map. The goal is to uncover the identity of the mastermind who has been sending assassins to the island and to uncover the vast treasure that is hidden there. However, just as they approach the island, their plane is shot down by snipers, and the group crash-lands on an island of death. What they find there is an end-of-the-world landscape of piles of decaying weapons and nuclear missiles, and "garbage men" who were once used as weapons but have been discarded, roaming the streets. The island is shrouded in fog, filled with a poison that can kill within 24 hours, and there is no escape. The ruler of the island, Muom, is determined to rule the world by selection and elimination under the banner of immortality. Faced with a "deathless enemy" who cannot be killed with a gun or a sword, Lupin puts his past, and his pride as a thief on the line in a battle of wits. Will Lupin be able to steal everything within 24 hours and escape the island alive?

The neighborhood cock of the walk is more than just an ordinary rooster—he's humanity's greatest defender! His opponents may be ten stories tall, but nothing is bigger than his stout heart and his fearsome battle cry—cock-a-doodle-doo!