New To This WORLD

This is about a guy called Park-Seo-Joon, who is 27 years old now.
He lost his past years memories due to sickness called amnesia. This sickness have been continuing from generations in his family, brother, sister ,everyone. He himself knows that there's no escape from this. But, he tends to get curious to know the *reason* for this sickness and what kinda person he was in the past years before he die alone.