I had a love-hate experience reading the manga. I am totally opposed to teacher-student relationship so perhaps it fired up my bias. The female lead started on as a strong and independent character but as the story progressed, she was dumbed down and lost all her senses. The male lead, Sensei, is yes very hot and handsome which actually hid his not so good character: selfish, immature and not to mention, perverted "love". Well, we all become stupid when in love. But if you are an adult and a teacher, you cannot "give in" to your student no matter what. It's not about the age difference, but understanding and respecting the role of a sensei: lead properly and NOT lead on your student.
The story can be summed up to this: sensei's the first love of the female lead and that is all. It was painful, frustrating, ILLEGAL and disturbing. But eventually, a second love can over ride first love. Sensei's fired up first love can be extinguished by Mamura's calm and stable second love.