RAIN, a Korean pop star, actor and pan-Asian heartthrob, is preparing for two concerts at Madison Square Garden this week by studying. Day and night, an English tutor trails him through Seoul, peppering him with conversational phrases as he labors to polish his singing, his martial arts-inflected dancing and, presumably, his chest baring.

You can never be too prepared to go global.

At 23, Rain, who has been labeled the Korean Justin Timberlake and the Korean Usher, is a serious and driven performer (with washboard abs, winsome looks and a Gene Kelly-like ability to leap through puddles while performing his hit song, "It's Raining"). He wants nothing less than to break down barriers, build cultural bridges and become the first Asian pop star to succeed in America.

"The United States is the dominant music market," he said through an interpreter in a recent phone interview from Seoul. "I would really like to see an Asian make it there. I would like that Asian to be me. That's why I'm studying the language, reading up on the culture and practicing every day to correct my weaknesses."

Since his debut in 2002, Rain, whose real name is Ji-Hoon Jung, has been riding what is known as the Korean Wave. As South Korean products, from cellphones to the music known as K-pop, have swept across Asia, Koreans have coined a new term, hallyu, to describe the phenomenon. Through his leading roles in soap operas and his music, Rain has become the personification of hallyu, which some see as a high-quality regional alternative to American cultural dominance.