If dialogue serves a purpose, here it will give an insight into the relationship of the characters by reflecting their comments as their thoughts of each other. It's like they're talking in hints. That's the feeling I got while watching this short film. I thought they chose an interesting way to tell a common plot- while keeping it open too. It's a complete story for me.

Most telling are the characters' comments about the birds, who can only be symbolic of them at two different stages. Because, when the birds are close together, the girls are glued to each other too- and when the birds have space between them, the girls have physical distance between them too. So the birds are them. Closeness represents love for Fuji and friendship for Maki. When there is distance, Maki wonders if it's love, but for Fuji it's definitely not. Being mere friends is half hearted for Fuji, since friends would go their own way when they're tired of each other, which is what the girls actually do at the end. Dusk sets on their relationship and like a break up, they go their separate ways.

I think you can interpret an untold story by reading between the lines. How Maki holds the umbrella for Fuji, how Fuji is affected by Maki's gaze, but it may not be romantic for her. How Fuji feels something in the hand movement they do, but it takes a while for Maki to get it. How someone catches them on the rooftop and they run off to the beach that's more free. How Maki loves the moon and Fuji similarly, from the bottom of her heart, and Fuji is silent.

When they first join their hands, they acknowledge the ways they don't match. The whole hand thing they do probably represents intimacy.