Miliam Blue no Mizuumi

Miriam's father considers Miriam Blue Lake to be the most beautiful in the world, and that is why he gave that name to his daughter, a romantic and dreamy fifteen-year-old girl whose life will change forever when a handsome boy, with big blue eyes, looks out his window. Because together with the awakening of love, secrets will also come, and Miriam will have to consider what is the future that she wants to live.

(Source: Arechi Manga, translated)