Overall: You should read it if you a sucker for such slice of life genre tragic/sad love stories. It reminds me of that American movie, "50 First Dates" and also the Korean Movie, "A Moment to Remember". If you like those, you would love this manga.
Story: It's amazing how you were taken in by situations that happened and not realize the significance of it until it was mentioned later on in the story. It had a wow effect on me as it also broke news about the character which shocked me. Great way of presenting information and keeping the reader craving for more.
Art: It is quality art work that's typical of manga from this period. Not many typical poses that showed off the beauty of the characters. They didn't sell sex (aka sex appeal is not that high) but it's really great at portraying scenes as needed by the story.
Character: Somehow I could understand the feelings of the character through how they were portrayed. You can understand that because of the character type of the female lead, that she would fall for the guy. How the guy would fall for the female lead because of her character too. Not amazing characters but they are interesting enough to sustain interest.
Enjoyment: Somehow each chapter kept me hungry for more to find out what's going to happen next. This story made me feel the pain/aches of being in such a realistic relationship. I seriously couldn't wait to finish the whole story in one go.