I assume you are talking about the 2nd boss in Okinawa. The one that throwing knives at you at far. 1st of all, use all the furniture in the room to beat him up. Use every possible items that you can to drain his health. 2nd, make sure your characters are sufficiently leveled up. Try to get at least the 2 finishing blows where you can press Triangle, Triangle after normal punches. I normally stick to Square, Square, Square, Triangle, Triangle. When the boss goes into heat mode, you have to be more careful as he is prone to interrupt you mid combos. So, stick to smaller combos then sway away, rinse and repeat to slowly chip away his health. Then you should be able to go to the Super Finishing Move when near the end. Good luck, took me a while in the 1st try but with some health supplements, managed to beat it Oh, and using a weapon WILL HELP A LOT!!!! Use the Extendable Staff! If you think this is hard, wait till you meet the Artful Dodger in Kamurocho