17-year old high school students Ludwig and Johann are best friends. They both share a passion for rowing and have won many contests in their fast boat "Coxless Pair". But gradually, sensitive Johann is more and more taken in by his spirited friend Ludwig. With their close-cropped haircuts and identical clothes, the inseparable duo appears as a pair of twins. Their sport and their appearance binds them closer and closer together. But then, Johann falls in love with Vera, Ludwig′s sister. At first, they try to keep their relationship a secret. But when jealous Ludwig starts to suspect that there is something going on between his best friend and his sister, things turn into a catastrophe.