Kimi to Himitsu no Hanazono

From Enchantment Scans: Farewell, my manly side! Ayase Natsu, with the goal of becoming more ladylike and popular, enters the prestigious girl’s boarding school. On the first day in the dorms, Natsu finds out a secret about her roommate, Konno Fujio, who is Natsu’s ideal model of a girl. How will Natsu react...?!