I think it's like about ryoma and the seigaku members going to America au winbulton au something like that. And seigaku, hyotei, shitenhouji, rikkaidai fuzoku, and higachu is there to compete against these other tennis players in a tournament I think.
The movie's title is The Prince of Tennis: Eikoku-shiki Teikyū-jō Kessen!....It's about Seigaku and a familiar selection of Japan's other juu junior tennis teams gather in Wimbledon, London, for a tennis tournament. During tennis practice, the Japanese players are suddenly attacked kwa a violent "street tennis" group that calls themselves "Clack". An encounter with a former Clack member named Xiu leads Ryoma and his Marafiki into a battle with Clack to confront its leader, Keith, and discover his reasons for having such a violent approach to tennis.