The Weapon Workshop, run by the eccentric Kamiyama, allows Kiryu to craft new weapons and modify existing ones. By collecting materials found throughout the city or dropped by enemies, you can create powerful custom gear. Modifying weapons can increase their attack power, durability, or add special properties. This is crucial for obtaining the best equipment in the game.

Kamiyama Works:
- Location: Found in both Kamurocho and Sotenbori.
- Crafting: Combine specific materials to create new weapons and gear. Recipes are often unlocked through substories or by finding blueprints.
- Modifying: Enhance existing weapons by increasing their stats or adding elemental effects. Requires materials and Yen.
- Materials: Gathered from street fights, minigames, substory rewards, or purchased from specific vendors.