Dynasty Warriors 5

Battle of Chang Shan
Yuan Shao's forces

Defeat Lui Bei, Guan Yu, and Zhang Fei within 1 minute of the first dying. Don't start with Liu Bei as the others are his subgenerals and will run away after his defeat. It seems like a hard one to complete, but if you take a well ranked character, do it on Easy, and save before starting to fight any of them it shouldn't be too bad.

What worked for me was to fight Zhang Fei until he had a small amount of health left and then go to Guan Yu and fight/kill him. Zhang Fei followed me, so I took them both out at the same time. Jump on your horse, ride to Liu Bei, and send him to his brothers quickly and Red Hare should be yours. Check the battle log for the valuable item message and the location. If it's not there, then you might have to start from the save.