Dai-Yamori-Kaiju: The Giant Gecko Monster takes place in Osaka in 2005. Paul Dunwich is a genetic scientist and father that has his whole world torn apart after the 100-meter-tall Dai-Yamori levels Osaka killing the people closest to him along with most of the inhabitants of Osaka. After the monster resurfaces in the Osaka Harbor it's up to Paul to get his son Alan & Alan's friend Saki out of the building alive as he's presented with the impossible task of saving both of the children.

From the ashes though he will find a new purpose to his life, as well as, the lives of those he saves to possible even save the world from Dai-Yamori-Kaiju when the monster returns to wreak havoc once again.