Yun Rival script Yun: Hey! Chun li: Oh it's you, uhh......Yun right? Yun: Yeah Chun li: Why are you here all alone? Where is your brother? Yun: I'm fighting alone. Chun li: Well why won't you skate your little board and ride home. Yun: Hey, Don't talk about my board! Let's have a match now and I'll show you a ride home. Chun li: Hope I don't hurt you. Your mother would be upset. Yun: Shut up and Fight!!
They were released during the Ultra Street Fighter IV period of the game, and I assume the dev team at Capcom decided not to animate a whole new animation for their rival scenes either due to budgeting, time constraints, or some other executive decision relating to practicality