Wrath of the Kaiju is a 304-page hardcover adventure supplement for 5E-compatible tabletop roleplaying games, built to deliver cinematic monster-hunting scenarios that integrate directly with ongoing campaigns and pair naturally with Ryoko's Guide to the Yokai Realms. Inside are five large-scale adventures that send player characters across dangerous environments to confront towering kaiju-class threats. Each successful hunt unlocks structured rewards, including harvested monster materials that can be crafted into unique equipment, companions, or narrative upgrades for future sessions. Every scenario is designed for straightforward table use, enabling Game Masters to introduce dramatic, high-impact encounters with minimal preparation. From battling river-spanning koi dragons to surviving the devastation of colossal kabuto beetles and uncovering the sorrowful legend of the ghostly bakekujira, each hunt focuses on tactical challenge, memorable spectacle, and meaningful progression. Created as an expansion to Ryoko's Guide, this supplement supports long-form monster-slaying campaigns while remaining fully usable as standalone adventure content for any compatible 5E fantasy setting.