Afterschool Juliet(2008)

Houkago Juliet

Hana Yamada is a high school girl. Her boyfriend is the mean Mr. Kido, her school doctor... Hana can't tell anyone that she's dating him, but nonetheless, she's totally happy. Cracks in their relationship begin to appear when another girl starts hitting on Mr. Kido, who insists on keeping his past a secret... During this troubled time, a man that looks identical to Mr. Kido proclaims his love for Hana and steals a kiss from her. A daring story about the secret love between a student and a teacher. It includes a special extra chapter "Morning Star and the Sun's Dream".

(Source: Renta!)

Note: Includes one extra chapter.