Masashi Esaka is a supporting character in the soccer anime Hungry Heart: Wild Striker. He is a midfielder for the Jyoyo Akanegaoka High School soccer team and is often called by the nickname Osaka, a playful mispronunciation of his name used by the protagonist, Kyosuke Kano.

On the surface, Esaka appears to take everything in stride, often presenting a cheerful and easygoing demeanor. His behavior initially seems to position him as a source of comic relief, but this impression belies a much deeper commitment to his team. Beneath his laid-back exterior, Esaka is genuinely passionate and deeply cares about the well-being of his teammates as well as the overall performance and success of the team.

This serious dedication to the sport and his school is formally recognized by the team's coaches, Sako and Kamata. They select Esaka to become the new captain of the Jyoyo soccer team, a decision made in acknowledgment of his excellent attitude and his strong drive to constantly improve both himself and the squad around him. His elevation to captain is a significant moment in the story, confirming his role not just as a supportive friend but as a natural leader whose quiet influence is essential to the team's dynamic. An episode of the series is titled Captain Esaka, underscoring the importance of this development in his character arc.