Demeter

Usually being beaten up and hospitalized by the school bully isn't considered to be a great turning point in your life.

Fifteen year old Ryder faces some of the common challenges of any young man his age: isolation, sibling rivalry, first love, and bullying. Life takes a sudden change when he is invited, along with his sister and five classmates to spend a year abroad.
Read the contract! Instead of going to Europe on Earth Ryder and his friends are conscripted for a year of service in Demeter, an asteroid over a hundred light years from Earth.
The good news is that Ryder gets closer to his classmate Cynthia Flores and he gets to develop his talent at gaming with systems that deal with real life scenarios including saving Demeter itself from invasion. The bad news is that his reckless younger sister has a talent for mischief and disaster. And now, she and Cynthia have been kidnapped and it's up to Ryder to figure out how to save them before someone kills them all.