The Blue Brothers - Tom, Carlos, David, and Shiro, are four half-brothers studying in an elite all-boys high school called St.Patrick's Academy. They find out that their father who also owns the said academy is going to die in three months, leaving the school bankrupt. As an evil competitor plans to do a hostile takeover and get the 'blue academy' at all cost, the teenage brothers need to find the four keys essential to unlock a hidden treasure buried by their grandfather years ago, for the academy to be saved.

Alfred wakes up from a deep sleep and finds himself in year 2012, a period quite ahead of his time. His body never changed for he is still a young, 21 year-old man. As he tries to remember what happened, only one girl came into his mind - Helena, the girl whom he loved dearly in an unforgettable summer of 1947. Adjusting in the 21st century, he surprisingly meets Hanna, a young girl who looks exactly like Helena.