Shizuku, who always puts others’ feelings before her own, spends her days secretly posting unspoken thoughts on the 150-character SNS platform “Letter.” One day, her classmate Kakeru asks her to help write a story together to enter a Letter contest. To find inspiration, the two begin going out in search of seasons and colors. As they spend more time together, they gradually grow closer— but that also means confronting the secrets each of them hides deep within. This is the story of two transparent souls who longed to be someone they couldn’t become— and how their tale quietly begins to unfold.