Tenshi na Kimi wa Akuma na Kareshi!?

When Eiyu met her childhood friend for the first time in 10 years, she found that he had become a handsome devil! Eiyu had been a hard worker since he was little and could do anything. However, Yuki-chan, who lived next door and was as cute as an angel, was a genius, and Eiyu could never match her. Eiyu was relieved when Yuki-chan moved away, but when Yuki-chan returned after 10 years of transferring schools, she had become an incredibly handsome man! Wasn't Yuki-chan a girl? On top of it all, Yuki also seems to have a really bad personality!

(Source: Ciao Plus, translated)

Note: Includes three extra chapters.