Yuri and Amber are best friends, They met when Amber was running with a shot leg when Amber was twelve y/o. Amber lived with Yuri's parents, she was transferred to China to learn all types of martial arts and when she was sixteen, she came back to Korea to meet up with Yuri and live there.
Stepping back on the land that she was shot, she didn't want revenge because her mother had told her no, don't come back for revenge, remember us but yet forget us.
When she got back in Korea, Yuri's parents enrolled her into a school, a private school, SM PRIVATE HIGH. That is where the story unfolds....