Before we Begin...
This week is a rare week.
The chance to wrap an entire review in one shot. From beginning of manga to end.
Well, it helps that the title is short, but in anycase it's a complete review here in one shot.

Graphic Novel 1 to 2
Tsubasa doesn't seem to be getting along very well in her new school.
Moving to Hokkaido with her father so he could learn from a master baker there (his job skills being as a baker) she has found herself not adjusting very well to her new life.
Add to that her longing for her mother who died soon after her birth and we have one unsettled and very "Fish-out-of-water" girl who just wants to fit in somehow.
So when she spies lights in the sky, and goes to look for her runaway dog she finds a lot more than simply her beloved pet. She finds a downed alien ship with a tall blonde male in strange skintight bio-armor, the strange bizarre alien he's pursuing, and... a twin sister?
In the heat of crisis as they're attacked by one of these bizarre alien creatures (called Magure) she ends up bonding with a spare one of the bio-armors this male ("DD" being the closest our language can come to his name) held (compacted into a tiny sphere) and becoming a "Figure" (humanoid looking bio-armor with great power) and bonds with said armor. When, after the battle, they separate however -- the armor does NOT return to it's normal form, it turns into a duplicate of Tsubasa instead and calls herself "Hikaru".
At first it looks like they'll be together for a short time but it seems that DD needs both Tsubasa and Hikaru to defeat the remaining Magure, which kicks of a touching, heartfelt, funny and very deep two Graphic Novel story which tells of these new "twins" lives and how it touches upon others in their class.
Even as backup arrives on the planet (a female with a history with DD) she in turn also becomes entwined in the story of these new "twins" as they continue to hunt down the last of the Magure.
A beautiful story with things that I didn't even see coming, it's strong and lovely and a must have read without question.
Ok. Breakdown time.

Figure 17 Breakdown (Complete)
What's Hot? These two Graphic Novels just stood out for me. A truly engrossing, lovely, deep and touching story from beginning to end. It's short, way short, and yet it's a worthy read. Kudos to Genco-Olm and Guy Nakahira for making a title worthy of your collection.
What's Not? I wish it was longer, and the story of Hikaru/Tsubasa lasted longer... but for the time we spent together storywise it was well worth it. A beautiful story, though short.
Moments to Remember? It's all memorable, but the interactions between both Tsubasa and Hikaru, and Tsubasa and her classmates (once she becomes more confident) are just some of the highlights.
What to Ignore? Well... there is something... but that is something I would like to discuss with over an interview with Mr. Genco-Olm if possible. I know it may never happen, but being the eternal optimist I will keep myself open to the possibilities. Who knows? Maybe one day it might happen... one day.
Overall? It's short, and yet your investment in having these two books will be well worth it. A lovely and touching story it really grabs the reader and holds their attention from beginning to end. Short, yes, but that doesn't mean it's not a good read. I liked it, and hope you find it so you can try it out yourself.
(If ADVManga ever makes a boxed set of these 2-book mangas I'd love to see a set with this title and Chrono Crusade for starters as a set. It's a must read book, and well worth checking out.)