In Season One of World Trigger, trainee agent Osamu Mikumo defies Border regulations to protect his classmates from a Marmod assault near their school. Outmatched and outgunned, he relies on tactical thinking and sheer willpower — until Yuma Kuga steps in to save the day. The episode builds the foundation of an unlikely friendship and signals the kind of principled, self-sacrificing hero Osamu will become throughout the series.
Episode two of World Trigger digs into the odd-couple dynamic between Osamu and Yuma as their unlikely friendship begins to take shape. Yuma is powerful but clueless about everyday Japanese life, making Osamu his reluctant guide. When Trion Soldiers invade the school, the two are forced to act, and Replica emerges as a quiet but crucial figure — part navigator, part protector, and perhaps the closest thing to family Yuma has.