The hapless American Little League baseball team known as the Bears stumbles upon an unexpected opportunity when they catch a glimpse of the Japanese junior baseball champions on television. These champions have issued an open invitation to American teams, yet none have accepted the challenge. Inspired, the Bears decide to rise to the occasion and take to a local morning talk show to drum up support for their audacious venture.
Enter local hustler and con artist Marvin P. Lazar, portrayed by the charismatic Tony Curtis, who, amidst contemplating his mounting debts, can't help but get an idea upon seeing the Bears on TV. He shares this idea with his associate, Louis the Gambler, played by Lonny Chapman. Marvin proposes that for a hefty sum of $10,000, Louis can invest in his plan to take the Bears to Tokyo and broadcast the game to an American audience. However, Louis declines, citing Marvin's existing debts to him. As luck would have it, the Bears soon appear at Marvin's office, where he deceitfully pretends to have already secured funding. He hands out contracts to the children, claiming approval from their parents and vows to make them famous as their new manager and coach. Little does he know, the team member Ahmad Rahim, played by Erin Blunt, insists they must bring along his six-year-old brother, Mustapha.
Fast forward several days, the Bears arrive in the bustling heart of Tokyo, where they meet the Japanese team and their coach, Shimizu, played by Tomisaburô Wakayama. Soon after checking into their hotel, Marvin's troubles begin as he presents two credit cards to the hotel management, which leads to a comedic series of events as he desperately tries to secure televised coverage for the much-anticipated exhibition game.
During the practice session, spontaneous antics unfold as Marvin pitches various narratives to Eddie, an American journalist played by Jerry Ziesmer, determined to spin the Bears' story to attract viewership. Despite the star player, Kelly Leak, played by Jackie Earle Haley, hitting a home run, his teammates struggle, resulting in Japan scoring a dominating ten runs against the Bears' single, disappointing score. Eddie warns Marvin that viewers in the U.S. are unlikely to tune in to watch an American team face defeat.
On his trek back to the hotel, Kelly encounters a captivating Japanese girl, played by Hatsune Ishihara, who captures his attention with her beauty. However, she only speaks Japanese, leading Kelly on a comical adventure as he attempts to communicate using a dictionary. This budding romance flourishes as they share a dinner and learn about each other, despite the language barrier.
Back in the hotel, Marvin faces the harsh reality of his situation—his promotional skills are, unsurprisingly, not bearing fruit. He’s forced to come clean when the hotel realizes he lacks the funds to pay for their stay, drastically cutting up his credit cards. The Bears, now disillusioned, confront Marvin about his deception, yet Mustapha stays supportive of Marvin, revealing the child's unwavering loyalty.
Determined not to be beaten by adverse circumstances, Marvin enters a wrestling ring against Japanese champion Antonio Inoki. Contrary to his expectations, Marvin finds himself on the receiving end of a real wrestling match full of chaos and humor, as Mustapha heroically intervenes in a moment of panic. The game's unusual twist garners media attention, sending the Bears shooting up in publicity.
While the excitement grows, the team rides a train to their game location, only to discover Kelly is missing. Kelly is blissfully wandering the streets of Tokyo with Arika, enjoying each other's company. However, Marvin realizes he is falling behind on his responsibilities as coach and manager. Later, Shimizu observes the media buzz around Marvin with skepticism but ultimately acknowledges that their mutual interests may align since success could benefit both teams.
As the Bears begin to see some financial success, Marvin overlooks their contentment with their old uniforms and insists on presenting them with brand-new gear. While all seems well, the underlying tension between Marvin's hustling nature and the team's genuine desire to play emerges. When Ahmad angrily confronts Marvin about his unscrupulous methods, Marvin starts to reflect on his actions.
On the day of the game, Marvin introduces a trio of talented Texas players to bolster the Bears' chances. However, the Bears, feeling betrayed by Marvin's manipulations, resist the changes. Disregarding their objections, Marvin proclaims the Texans will turn them into heroes. This leads to turmoil and, in a twist of fate, a riot breaks out, forcing officials to cancel the game.
Against this backdrop of chaos, Marvin realizes that camaraderie is more valuable than the relentless pursuit of fame and fortune. The network director's threats push Marvin to weigh his contractual obligations against his integrity, culminating in a decision to step back from the relentless promotion. Embracing a newfound teamwork spirit, Marvin proposes a joint exhibition match in Cuba for the following year, bringing the two rival teams together for a brighter, more fulfilling future.
