The Straw Hat crew stumble upon a giant sky-tree inhabited by monkey-humanoids with a dark past. Determined to save the Blue monkeys in the lower canopy from monster salamanders, they find themselves in more trouble than they bargained for that could mean life or death for captain and crew.

Daichi and Sugawara never expected to have three lives dependent on them when they're only in their mid-twenties. But they wouldn't give up on those three brats for the world. When they believe two more children are going to be added to their odd family, they are given a shock of their lifetime. Their family of five just became a family of nine. AUFamily

Luffy saved his nakama, but at a heavy price. Now the captainless crew must find a way to get him back while he finds himself being used as a test subject to create a seastone gas.