Yakuza 3 is full of hidden items and collectibles that reward thorough exploration:

- Locker Keys: These small, glowing keys are scattered throughout Kamurocho and Okinawa. Each key opens a specific locker, which contains valuable items, weapons, or crafting materials. There are 50 locker keys in Kamurocho and 50 in Okinawa. Look for them in alleys, on rooftops, and behind objects.
- Coin Lockers: Once you find a key, head to the nearest coin locker station (marked on your map) to open the corresponding locker and claim your prize.
- Weapon & Armor Drops: Certain enemies, especially mini-bosses or those encountered in specific substories, can drop rare weapons or armor.
- Crafting Materials: Break open every trash can, cardboard box, and destructible object you see. Many crafting materials are found this way.
- Revelations: As mentioned in the 'Side Quests & Activities' section, finding all Revelations unlocks powerful Heat Actions.
- Completion List: The Completion List in the pause menu tracks various achievements, including finding all locker keys, completing all substories, and mastering mini-games. Completing these often unlocks special rewards.
Take your time to explore every corner of the map. Use the first-person view (L2/LT) to spot small, hard-to-see items.