An event related to the 20th OP Anniversary that took place in in December 2017, consisting of 15 stamina and 20 stamina events. It has moderate difficulty - most teams should be able to clear it. It features Chopper, Nami, Brook, Zoro and Sanji (boss), and drops all of their books as well as some boosters and evolvers.
Video: https://www.youtube.com/watch?v=hq7vubSHz7g
This event followed Showdown! Straw Hat Pirates (both events had exactly the same name - see banners). Should not be confused with the much harder Straw Hat Mission! which occurred around the same time but was much, much harder.