With the Gyaos re-emerging, Gamera's ties to humanity have been severed with his bond to Asagi broken. Nagamine and Asagi investigate while an orphaned girl named Ayana discovers a new creature she names Iris. Nagamine and Asagi must reach Ayana before she takes her revenge on Gamera, who she blames for the death of her family.
前田愛
as Ayana Hirasaka
中山忍
as Dr. Mayumi Nagamine
前田亜季
as Young Ayana Hirasaka
藤谷文子
as Asagi Kusanagi
Yû Koyama
as Tatsunari Moribe
安藤希
as Miyuki Moribe
伊藤隆大
as Satoru Hirasaka
山咲千里
as Mito Asakura
手塚とおる
as Shinya Kurata
螢雪次朗
as Tsutomu Osako
本田博太郎
as Masaaki Saito
堀江慶
as Shigeki Hinohara
