As far as Junichi Tazawa is concerned, the most rebellious acts in his 22 years have been ignoring his homework and sneaking home after sunrise. But as the first high-profile Japanese baseball prospect to turn down his nation’s leagues to entertain offers from Major League Baseball teams, he has found himself straining relations between baseball entities on two continents, with accusations of talent raiding and defiance of decades-long understandings.

Many Japanese baseball officials are outraged that United States teams are courting Tazawa, a hard-throwing right-handed pitcher, because they insist it is long-established practice for amateurs like him to be strictly off limits to major league clubs. Even some American general managers, including the Yankees’ Brian Cashman, agree.

Major League Baseball officials maintain that the letter of their protocol agreement with their Japanese counterparts, Nippon Professional Baseball, does not forbid either league from courting amateur talent from the other’s nation. When one Japanese representative characterized the rule as a gentlemen’s agreement during a meeting in New York, he was angrily rebutted by a Major League Baseball official, according to two attendees.

The Tazawa dispute extends beyond one pitching phenom and an interpretation of honor. The Japanese major leagues have already seen established stars leave for American clubs, and amateurs following Tazawa’s path away from those leagues could further hurt the leagues’ long-term viability.