A true honor student, role-model for all the guys and liked by everyone in school alike. His personality, always ready to be righteous and help the weak. But nothing of this is really true. Truth is he steps on everyone and everything in order to get his way and be seen as the 'perfect' being. He's also, in the truest sense of the words; extremely competitive, a sore loser and somehow resembles a person with mental issues more so than never. He hides his true face at school and in public; giving him a twisted personality that acts 'friendly' for no other reason than his own social benefit.
As the story progresses, more of his real personality is revealed. And despite his true nature being quite shocking; the eventual truth situations lead him to are even more shocking and a lot worse than the actual truth.
Despite the flaws in his personality; he actually has a good side to him once a while. It's just that whenever he does something good; as rare as it is, he gets seriously misunderstood, leading to a reputation-killing result.
His only known family is his dad (Kang Joosham). His mother supposedly left his father after figuring out his 'true personality'. His dad seems to suffer from the same mental issues.
Shinji looks pretty good, has a pretty nice body and athletic abillities. Being able to dash 100 meters in the span of 11 seconds. He has also shown to have great reflexes.