Ichiban Chikakute Tooi Hoshi

Stargazing! You wouldn't have guessed how such a simple hobby turned into some of the most interesting things anime could embellish upon. Though Nearest and Farthest Star is basically concept animation, KoiAster is a TV anime. This works more as a KoiAster --> Nearest and Farthest Star rec but you can do you. 

Distance. Despite their short lengths, the pair convey a message quickly with ease suffering no losses in the system. One about distance taking some shape or form, with studying in the process. No real point in saying what the plot is, watch it for yourself if you wish too. Less than 5 mins combined.