There are few places like the Square Nadar that open their doors to everyone, with or without a dog. Guillaume, the park's mediator, is constantly meeting new people and reuniting with regulars, his friends, every day at the experimental dog park in Montmartre. His goal? To create an osmosis, to meet new people and it works perfectly!

Billy Johnson is a proud, one-meter-long cat with the fangs of a vampire who has chosen green beans as his drugs. Sébastien, director and scriptwriter, is fascinated by this half-Maltese, half-siamese creature, which sprawls himself across his appointed chair.

After spending his childhood studying, observing and drawing animals, Guillaume became an art agent. Moving between their home in the Loir-et-Cher and Paris where they have a second home, Guillaume and his husband live with about thirty animals... all of them are very unusual.