Gamera 3: Revenge of Iris (1999)

Three years have passed since the attack of the Legion, and the world is once again plagued by Gyaos attacks in diverse locations such as the Philippines. The flying monsters, thought to have been wiped out by Gamera, are now reappearing in increasing numbers across the globe and have been evolving out of control. Mayumi Nagamine, noted ornithologist, returns to aid the Japanese government in addressing this threat. A graveyard of Gamera fossils has been found at the bottom of the sea. Shadowy government agents Mito Asakura and Shinya Kurata, the former with occult beliefs and hinted by Kurata to be descended from the ancient advanced civilization that created Gamera and Gyaos, are meanwhile working to a different agenda, with Asukura believing Gamera to be an evil spirit that has to be stopped "to prevent Heaven and Earth's destruction."

Tragedy strikes, however, as the monsters take their conflict to the populated Shibuya district of Tokyo. Two Gyaos glide across the city skyline, relentlessly pursued by Gamera. He manages to blast one of them with a plasma fireball over the city, sending its flaming body into a collision with a crowded subway. Gamera bursts into the station in order to finish off his foe, incinerating the dying Gyaos along with several city blocks. Gamera then pursues the second Gyaos, firing several plasma fireballs at it until it is destroyed. Gamera then flies away into the night sky. An estimated twenty thousand human lives are lost in the battle, and the Japanese government orders Gamera's immediate destruction.

Meanwhile, a young girl named Ayana Hirasaka copes with the loss of her family, who were inadvertently killed by Gamera during his Tokyo battle with Super Gyaos in 1995. Consumed by a maelstrom of hatred and despair, Ayana finds friendship in the oddest of places: a stone egg sealed within an ancient temple in the village of Asuka where she now lives. The egg hatches into a small tentacled creature, whom the girl names "Iris," after her dead cat. Iris becomes the focus of Ayana's quest for revenge, as she seeks to raise her own monster and take vengeance against Gamera.

Revenge comes at a price, however, as Iris attempts to absorb Ayana in the process of its growth. A young man named Tatsunari Moribe manages to free her from Iris' cocoon, but its taste for humanity is far from quenched. It escapes and kills the entire populace of the village. Iris then grows into his monstrous adult form and continues terrorizing the countryside. The JSDF assaults the monster, but Iris easily wipes out the attacking platoon before taking flight.

Iris flies toward the city of Kyoto, pursued by the JASDF, but is intercepted in mid-flight by Gamera. The monsters engage in a high-speed battle in the night sky, Gamera using his saucer-like locomotion to batter Iris. The JASDF intervenes, however, knocking Gamera out of the sky with a tactical missile strike. Iris then proceeds unimpeded to Kyoto, where Ayana has been taken by Asukura and Kurata, with Asukura deliberately trying to use the girl to summon Iris. Nagamine and Asagi Kusanagi, the girl once psychically linked with Gamera, retrieve Ayana and attempt unsuccessfully to get her out of Kyoto, as travel has been halted by a typhoon. Kurata expresses a belief that Iris has been deliberately created to kill Gamera so that the Gyaos will wipe out modern humanity, a "decadent civilization."

Inside the train station in Kyoto, Ayana lends her will to Iris, as Gamera dives into the city and fires several plasma fireballs toward Iris. Iris easily bats them away with his tentacles, and the city erupts in flame. The two monsters engage in a melee, but Iris easily gains the upper hand, impaling his foe with the spear on his arm. Both monsters barrel into Kyoto Station, killing Asakura and Kurata. Iris knocks Gamera to the ground and leaves him for dead, bleeding profusely from the hole in his body. Iris then absorbs Ayana once again, this time against her will.

From within Iris' body, Ayana experiences the monster's memories of killing her village, and realizes that her hatred and bitterness over being an orphan motivated the monster she raised. Just as she has her epiphany, however, Gamera plunges his hand into Iris' chest. Gamera manages to wrench the girl free, robbing Iris of its human merge, but it counters this by staking Gamera's hand to the wall with one of his extendable, sword-like arms. Nagamine and Asagi, trapped within the train station's wreckage, watch helplessly as Iris begins to siphon Gamera's blood, using it to create plasma fireballs with its tentacles. Before they can be launched, however, Gamera takes action, choosing to instead blast off his own impaled hand. Iris fires two plasma fireballs, but Gamera then points his stump arm toward the incoming attack, absorbs them, and forms a fiery plasma fist, then drives it into Iris' wounded chest.

Iris shrieks in agony and explodes, blowing the roof off the crumbling train station and obliterating Iris once and for all. The comatose Ayana still clutched in his fist, Gamera sets the girl down where Nagamine and Asagi are hiding. The women are unable to revive her, but Gamera lets out a roar and Ayana opens her eyes. Gamera leaves the girl wondering why he would save her life after all she had done, while Moribe runs to Ayana and comforts her. The four survivors watch Gamera leave the station and enter the ruins of Kyoto. Nagamine remarks that it appears Gamera will continue to fight even if he is alone, but Asagi states that Gamera is not alone, knowing that humanity will fight by his side once again. As Gamera roars in defiance, the Gyaos, thousands strong, descend upon Japan.