Katrin, it’s possible to look at the story structure in three acts with the traditional approach to a romance, albeit with a bittersweet end:
Boy and Girl meet
Boy and Girl fall in love
Boy and Girl move on with their lives
That said, as your take points out, it would seem Chazelle definitely has something going on using the seasons as kind of chapter headings. Reminds me of Juno which also used the seasons to mark the passage of time.
Thanks for that, food for thought. Want to digest the whole season thing further, consider if there’s anything deeper going on thematically…