Don't Touch, Maria

Himari, known as "Saint-sama" around school, is heartbroken when Daiya, her childhood friend and long-time crush, gets a girlfriend. Still distraught, a junior boy, Itsuki, suddenly confesses to her, "I've always liked you"...? Although she still has feelings for Daiya, she can't resist Itsuki, who aggressively comes on to her, unconcerned about her saintly reputation...?

(Source: Manga Park, translated)