Yuck. Couples kissing on the mouth are gross. And the worst is, you can't miss them: when people are about to kiss, their lips become all pink and shiny. Little Léo laughs at them, just like all the kids at the summer camp. But he has a secret he won't tell his friends: his own mouth has actually begun glistening. And, in reality, Léo desperately wants to give kissing a try.
Alain, a former mountain guide, decides to change his life and become a teacher. He finds himself faced with colorful ninth graders who are not interested in anything. Seeking to motivate them and bring them together, Alain decides to organize an outing... in the bowels of a glacier. The students discover a breathtakingly beautiful world of ice. The idea that this glacier could disappear is unbearable for them. Trained by Alain, the students throw themselves body and soul into a crazy project: to prevent the glacier from melting and nothing can stop them!