Himejima-kun, Ato 20 Senchi!

Himejima-kun, a first-year high school boy, has an unrequited crush on his classmate Hoshimiya-san! However, Himejima-kun is very worried about how "Hoshimiya-san is much taller"... A frustratingly cute classic romantic comedy about "height differences"!! (Source: Princess, translated)