This repository is a modular library for loading and using VRM (Virtual Reality Model) avatars within three.js applications. It provides a set of GLTFLoader plugins that parse VRM extension schemas—covering humanoid bone rigging, facial expressions, spring bone physics, node constraints, animation clips, and custom materials (MToon for anime-style rendering, HDR emissive multiplier, and VRM0 compatibility)—and injects runtime objects into the loaded model. The architecture is composed of several packages: a core package handles humanoid, look-at, first-person, and expression systems; separate packages add spring bone physics, node constraints, animation playback, and material extensions. The main entry point is the VRMLoaderPlugin, which composes all sub-plugins. External dependencies are three.js (with version-specific compat shims) and the GLTF loader. The library is designed for browser-based 3D applications, with extensive examples and debug helpers. The codebase demonstrates strong engineering practices: clear separation of concerns via the plugin pattern, dual VRM0/VRM1 support, comprehensive test coverage, and careful management of Three.js API drift. Notable reusable components include a Proxy-based matrix inverse cache, spring bone physics with dependency sorting, constraint graph with circular dependency detection, and a custom MToon material with outline generation and rim lighting. The monorepo structure with typed packages ensures type safety across extensions.