Ikenai! Runa-sensei Rいけない！ルナ先生Ｒ; Ikenai! Luna-sensei R

The legendary manga is reborn with new art! Wataru, a lazy high school student, is visited by the earnest and slightly airheaded teacher, Runa-sensei! So that Wataru can become a respectable adult, she gently starts giving him naughty private lessons! (Source: Comic-Days) --- Note: This is a remake of the 1986 original "Ikenai! Runa-sensei" manga