Italy from the '80s to the present day, through the dreams, loves, successes and failures of four friends.

Everyone in Marco's life seems constantly restless, from his brilliant but unhappily married parents to his own wife Marina, or even Luisa, the real love of his life, a girl he met during a fateful summer in the '70s and always stayed in touch with. Tragedy and fate seem to haunt him, yet he somehow manages never to get ensnared in the chaos—like his namesake, “the hummingbird”, he focuses all his energy at standing still.

In post-war Italy, the family of typical housewife Delia is in turmoil over the impending engagement of beloved firstborn Marcella. The arrival of a mysterious letter, however, will ignite Delia's courage to face her abusive husband and imagine a better future.

Marco is an anxious nineteen-year-old on the brink of adulthood, with three subjects to make up, a mother who lives with her smartphone in hand, and a brother who dreams of being an indie singer. He's anti-social and longs to experience love the way it used to be. Aria graduated the previous year, with "one day at a time" tattooed on her arm, and she lives each day as if it were her last. Following a wrongly memorized phone number, Marco and Aria meet and begin to develop feelings for each other... However, Marco is unaware that Aria lives one day at a time, not because she's as beautiful and rebellious as she tries to appear, but due to a degenerative disease that makes her go to sleep uncertain if there will be a tomorrow. A fun and gripping teen love drama that narrates the incredible and surprising journey that the protagonists will embark upon. All in pursuit of something as simple as it is complicated in today's world: falling in love.