Schoolboy Martin, bright but small for his age, has to move and change school because of his mother's new jobs, while only his father really tries to understand him. Even before reaches class he bumps into cocky, athletic rascal Oliver. It seems like Oliver's best friend Silke (a girl) taking to Martin will aggravate their tension, but she actually gets them to spend time together and grow closer. Martin even takes the blame, which neither parent understands, for Oliver smoking in class, a third strike meaning expulsion. Oliver's knavish mischief actually stems from his dad's drinking problem and its root, his ma's infidelity. When he runs away, Martin takes him in.
Tobias, aged 13, lives in an East German city and has learned to get by on his own. Then Max moves into the neighboring apartment, and he keeps it just like Tobias. He likes to determine how things should go by himself. Without further ado, Tobias decides to pass Max off as his father!