A Love Letter From the Future(2025)

Mirai Kara no Love Letter: Metsubou suru Sekai no Eiyuu wa Ore!?

Ian Ferkus, a 3rd-year at the academy, one day receives a love letter from 7 years in the future. It refers to Ian as a hero, along with the warning that "the world will end if the future is not protected." Now Ian must discover what this future is and how to protect it with the help of his friends.

(Source: Manta)