Asaba Naoyuki is an ordinary high school student. As a member of his school's press club, he's just spent the summer camping outside the local military base, in hopes of seeing the UFOs that are secretly kept there, according to local legend. Returning to school, he meets a strange girl, Iriya Kana, and gradually comes to realize that she is more than merely strange - and that a dark secret lies beneath the world that he knows.

某座小岛即将上演一出冒险戏剧，这正是伟大艺术家兰多鲁夫的引退演出。距离出海还有一段时间，路飞、乌索普、乔巴、娜美、山治等草帽海贼团的伙伴们闲极无聊，决定留下来观看演出。这几个无忧无虑的家伙跑进剧团的后台，穿上戏服玩起了角色扮演，乐在其中。就在此时，他们听到舞台上传来的砍杀声。原来，那正是兰多鲁夫与剧团成员在排练。这位老人气力已衰，却仍坚持演出，然而本应出演公主的女演员却突然辞演，离开剧团。眼看晚上的公演即将取消，娜美却突然走上前台主动请缨，草帽海贼团的各位也一拥而上要求扮演角色。兰多鲁夫难忘的告别演出即将开场…… 本片根据尾田荣一郎的漫画原作改编，为同名动画的SP作品。