Locker-Key-J4 Inside the secret casino. You need to wait until Chapter 7. The story will lead you to the lottery booth to buy a ticket. You are then given access to the
Yakuza Kiwami 2 Mega Guide – Farming Experience Points And Money, All Boss Battles, Coin Locker Key
Yakuza Kiwami 2: Sotenbori Locker Key Locations- All 50 Locations