STORY : Hiroshi and Misae have never been to a honeymoon trip to a foreign country. One day, Misae discovered an inexpensive and family-friendly holiday package to Australia and the Nohara family decided to make it their first honeymoon vacation. Hiroshi gets kidnapped upon arrival to Australia, leaving Shinnosuke, Misae and others on a dangerous journey. It turns out that Hiroshi is the key to a secret treasure. The remaining members of the Nohara Family must rescue Hiroshi, while a mysterious masked man and treasure hunters from all over the world are after him. The struggle is among three different groups in this action-filled treasure hunting adventure. 澳洲的秘境“古雷特巴巴布里夫岛”上，野原一家人正在尽情享受迟来的甜蜜新婚旅行。 但在这天夜晚，广志突然失踪了。 出去寻找的新之助他们看到的竟是假面族的村子里正在举行华丽的婚礼，而广志竟然以新郎的模样参加其中！ 这座岛上有个传说，如果在五十年一次的金环日食当天，将新郎献给公主殿下，就可以获得宝物作为奖赏。 而被选为新郎的人，就是广志……为打开宝箱的钥匙。 小新为了要夺回广志，而假面族VS一大堆的寻宝猎人VS野原一家人，这三组人马的“超激烈广志争夺战”爆发了！ 小新他们到底能不能抢回广志，平安回到春日部呢！？