Ruka to Ita Natsu

When I read the summary, I predicted that there would be romance with sci-fi being the subplot and the mangeka would exploit the relationship as the one being between two siblings to get more reactions out of readers. I've been proven mostly right, but the romance is weaved into the story seamlessly (and not vulgur), that you forget they're supposed to be siblings, it just seems so natural. It's not forced into the story and connects to the climax of the story, so without it there would be no story. Also, I was expecting aliens (because of the sci-fi tag), but was pleasntly surprised with a time travel theme.
About half of the manga is building upto a great climax where the protogonist has to choose between his family and his lover at the expense of the destruction of the world. While reading it, I thought it was just a regular sci-fi action filled manga, but it actually has a direction and makes one question their beliefs and values. You feel sympathic towards the protogonist because of the difficult choice he has make.

Story 6- It is fast paced, the manga is only 27 chps and contains good amount of action (especially martial arts). The first of the manga just seems to move in a predictable direction, while reading I was thinking that the author just seems to want to cover everything like romance, action, sci-fi and drama. But after 11 some chps, it becomes more interesting and more put-together.

Art 6- It's well drawn, not a lot of toning used, but very plain that turned me off in the beginning. The action scenes are actually very well drawn and are pretty long. The close up drawings of the characters in their most emotional states are also very detailed.

Character 7- I really like the main character Luca, her personality and perseverance. She is one of my most fav and has a great development in such a short manga. There aren't many side characterss, so less drama without them. The good and the bad guy is not clearly defined, it presents both their sides and let the reader decide.

Enjoyment 7- I'm solely basing my rating on second half of the manga and I enjoyed it a lot.

Overall 7- Because of its predicability and only little surprises here/there, but nothing that you hadn't expected. The manga could've been more dramatic and realistic, but I guess its length posed a problem for it to be such.

You can read it if you're looking for a short sci-fi, drama and romance containing manga. But it's really a presentation of what if situation and is intresting only because of that.