Chou gekijôban Keroro gunsô: Tanjou! Kyuukyoku Keroro - Kiseki no jikuujima de arimasu!!

In the beginning, Fuyuki has a dream where he sees burning figures and a gray Keroro Platoon. It ends with a strange moai statue calling "Fuyuki-dono." When he wakes up, Alisa Southerncross throws him a moai statue exactly like the statue it his dream. It bears an eerie resemblance to Keroro. He asks Keroro to take him to Easter Island, the birthplace of moai, to investigate. Keroro wants to build a secret base on the island and agrees to take him. (keroro.wikia.com)