I'm wondering that too
well, it's not a manga.. i was curious too since the art is beautifull, so i reverse image searched it.. its a novel, link here
https://www.novelupdates.com/series/the-hero-proposed-to-me/
(sorry to original commentor if i gave you two notifications)
here is a link, its a novel and not a manga as far as i know
https://www.novelupdates.com/series/the-hero-proposed-to-me/
Ty uwu
At the end of the first chapter is the picture with the black haired man and blond haired lady actually a manga? If so... What's it called? (人･∀･)