Kurokiya-san Wants to Lead Him Around by the Nose

Story

I used to have better grades than this fool! 3 years ago… Ruu Kurokiya, a Kuro Gyaru, is on her way to flunking high school. Her childhood friend, Straight-A student Tadao Tadashi volunteers as private tutor to avert her reckless path—but Ruu’s more focused on seducing him than learning, and their study sessions soon go wildly astray! When a “Gyaru’s Pride” clashes with Tadao’s “Take-it-Serious” attitude, who knows what will happen next! An unexpected rom-com so pure you can’t help but cheer it on! Note: Includes 9 extra chapters.

Synopsis via AniList (English).