The protagonist's sibling (gender depending on the protagonist's gender you choose) committed suicide by falling from a building six years ago.
From that day on, the protagonist has lived in immense distress.
Soon after the SAT tests, the protagonist received an email from the deceased sibling, in which it was revealed that was never a simple suicide, and that the truth was hidden in Lianhai Technology University which they attended before they died.
How could a dead person send an email anyway?
To seek the truth, the protagonist applies the college that their sibling mentioned in the email and joined the Student Union that their sibling used to serve, which leads to a series of battles against the notorious hacker group C.O.D.E in the college...
During which, the protagonist find themselves getting closer and closer to the truth.
