In a futuristic world, you are punished for every crime you commit by spending a given amount of time on Tera.
Tera is not a actual place but one created/simulated by a computer. Dispute this, you will feel everything that happens to your virtual body. Your actual body will be frozen and you will not age no matter how many years you spend in Tera. The goal of Tera is to convince you that the crime you committed was wrong.
For instance, if you hurt an animal, Tera will create a animal that you get really close so that you can understand why animals should not be hurt. This might seem like a good thing but it has its down sides as well. To see if you have really changed, in this scenario, it will have the animal you love so much killed. Worst part is that the person who does it looks just like you. Because of this, Tera has driven many to insanity. But its benifits outweigh the losses so it is still around and used for every criminal regardless of the crime.
The time you are in Tera is determined by how quickly you choose to repent not by the crime you committed. A person charged with murder could only stay in Tera for 2 weeks while a person charged with theft could stay in there for years.
...
Even in the future people want to love as long as possible. The story follows 2 orphans(siblings). Well ... one really.
So basically, the younger one, the boy is found to have astounding talent in medicine. On the other hand, the older one, the girl, had no talent at all.
One day when the boy was doing his medical training (he became apprentice of influencial doctor), the girl was lored out and killed by people who thought she was a burden to society and did not deserve to live. The boy was powerless to do anything as his master would not help him A few years later, he is a famous doctor who is said to be able to cure anything in the world. He heals one of the richest people in the world who was diagnosed with a incurable disease. Out of gratitude, he was give one wish (which rich person should be able to fulfill of course). He wants rich person to to investigate his sister's death and get revenge. Rich person agrees.
Investigation reveals that the killer was the young master of a corporation that deals in(fill in random abject name). The young master was put under trial for murder and sentenced to retribution in Tera. However, when the test* was taken, it was determined that he was genuinly sorry so he was let off according to the rules. Out of anger, the boy uses his resources and kills the young master. So he is sentenced to Tera.
After 10 years he is let out and finds that there is an astronomical amount of people who seel his medical expertise. In no mood to care about anyone anymore, he does not agree to treat anyone else. Those who seek him. start gifting him a variety of things and to get rid of them he agrees to treat 1 person per months.
A few months later... a man approaches him and claims to be his father. The man is a well known criminal who just came out of Tera. He had been sent there because he had killed every person who the person he hated knew. All because of a single insult...
*The test is used to determine what should be simutated in Tera.