In the wake of her mother's tragic death, French teenager Junie (Léa Seydoux) transfers to a different high school. Though Junie lives mostly inside her own head, her beauty and stoicism win her the attention of the entire male student population. Junie begins dating the gentle Otto Cleves (Grégoire Leprince-Ringuet), but finds herself intensely drawn to her youthful Italian language teacher, Nemours (Louis Garrel). When Nemours begins to reciprocate, serious complications ensue.

Ismael and Julie, who in the hope of sparking their stalled relationship, enter a playful yet emotionally laced threesome with Alice. When tragedy strikes, these young Parisians are forced to deal with the fragility of life and love. For Ismael, this means negotiating through the advances of Julie's sister and a young college student – one of which may offer him redemption.