Si Rain Celvero, simpleng babae na may simpleng pangarap. Ang makapagtapos ng pag aaral, ngunit sa hindi inaasahan ay napadpad siya sa isang delikadong paaralan. Ang Monstrous Academy. A school where students are divided into five Kinds: Keen - Students who have the ability to think clearly and to understand what is obvious or simple about something. Robust - The strong and healthy ones, are impressive and not likely to fail or weaken. Amiable - They are willing to accept the wishes, decisions, or suggestions of another or others. They have a friendly and pleasant manner. Probity - Students who have strong moral principles, students who are completely honest. Insolent - They are rude and arrogant, they have a lack of respect for others. Insolent, diyan nabibilang ang grupo ng D.A.R.K (Devil And Real Kings) Sila ang pinakakilalang grupo sa loob ng Monstrous Academy. Binubuo ng limang malalakas na gangster. Kinatatakutan ngunit hinahangaan ng karamihan, pero sa hindi inaasahan ay makikilala nila ang kaisa-isang babae na mag papabago ng kanilang buhay. At lahat ng iyon ay mag-uumpisa sa loob ng Monstrous Academy...