Before reading any of my reviews, please keep in mind that I am a VERY harsh critic. I do not hand out 10's easily and anything I rate 7 or higher I consider recommendation worthy.

Story: 7/10
The main story in itself would get a 9/10 from me, but I found that the cryptic, apocalyptic side story wasn't really necessary and took away from the overall story which is a shame because the main story is absolutely amazing. There were a number of sensual/sexual scenes in the story, but when you are reading you need to keep in mind that they are living in an age where (for the most part) the activity of sex doesn't seem to exist anymore. So for most of the manga we see the two main characters trying to discover themselves and each other which I found to be a rather interesting topic and moderately well done. From the start of the series I had a preconceived notion of how the series was going to end. Well it didn't quite end that way. I was very impressed how the manga-ka ended the series in a way that was actually quite unexpected for me. I sort of knew WHAT was going to happen, but as for HOW I was completely off the mark. The ending for me gets full marks, 10/10, due to its sheer impact. The human themes were a nice touch as well. The whole questioning of what makes us "human" was a nice touch. Especially considering the story takes place in a world where no one can be considered truly "human" by current standards. The fact that the most human character isn't human at all really drives that home.

Art: 10/10
A rare 10. I can't help it, the character designs were simple and very cute and attractive. The innocence of the two main characters was really emphasized through the character design. It really helped in enhancing the story. They were very well done and very appropriate for the story. The background art was also good. The house, the city, the lab, the tomato plant, everything. It was simple, yet detailed at the same time. A rather refreshing look at a largely unrefreshing world. This series is proof that manga art doesn't have to be complex to be good and effective.

Character: 8/10
Ai and Ikuru I would rate 9.5/10. Very well developed, very well portrayed with few flaws. Both were very likable characters and I'm almost tempted to give them 10's. Their interactions with each other were perfect. They really did suit each other very well. Nagi-sensei would be a 7/10. I found that she wasn't really developed properly. There were a lot of holes, especially with regards to her past, which probably should have been elaborated on. I really did like her character though, it's a shame she wasn't as prominent as she probably could have been in the story. Other characters would range from 1/10 to 3/10. Personally I believe that if you plan on adding a side story with side characters then said characters should be properly developed, which they weren't.

Enjoyment: 8/10
"Enjoyment" may not really be the proper word for this kind of series. The series as a whole was rather dark and depressing. Throughout the whole series there was a large, dark, ominous cloud hanging over the main characters heads. Which doesn't exactly fit my description of "Enjoyment". So perhaps a better word would be "Appreciation". The messages that this manga sent to me were priceless. Messages about humanity and love, about life and death and about reaching your dreams. You really do finish this series with a greater appreciation for what you have. I would give this a full 10/10 if (once again) it wasn't for the side story which served more as a distraction for me as I was reading.

Overall: 8/10
I currently have this rated as a 8/10, it's more like 8.5/10 and I am tempted to rate it a 9/10. This is a very touching story about love, life and humanity. The side story is a bit of a distraction, it wasn't really done well, was very cryptic and wasn't really necessary to the main story, but it wasn't that bad. If I had to rate the side story I'd give it a 5 (average, nothing special but not bad). What makes this series so special is the characters of Ai and Ikuru and their interactions with each other and other characters.

To anyone who likes to read romance and tragedy I strongly recommend this hidden gem. The story, the characters will remain with you, possibly forever. You will not be disappointed in reading this manga.