Story: The story is a typical student/teacher yaoi. But, it is original in the sense that not only does the student (uke) initiate the entire relationship; but the teacher (seme) is a completely rational adult and compels the student to stay on the "straight" and narrow.
Art: The art gives off a warm hearted and whispy type of feeling.
Overall: School based yaoi manga are not what you would call an original concept. Most of them can come off as something of a pedophilia-esque train wreck. To be done well and not have that type of feeling is something to be celebrated in Ashita no Kimi was Koko ni Ina. Give it a try and see for yourself.