You have to enter a code to unlock 2 player mode. Here is the code from GameFAQS.Unlock 2-Player modeAt the title screen, both players hold R1+R2+L1+L2. Then the 2nd player press START, and there will have sound effect if the code is entered successfully
This page contains co-op info for Onimusha: Dawn of Dreams on the Playstation 2. All information about Onimusha: Dawn of Dreams was correct at the time of posting. Information is subject to change. If you see any errors please email us.