On the night of a blood-red full moon, Kohinata Mangetsu, a completely ordinary high school student, returns to her classroom to retrieve something she forgot... and finds herself caught up in GRANBELM, a battle to determine who is the one true mage. Shingetsu, a girl participating in the battle, tells her that the world once overflowed with magic. Confused, Mangetsu tries to run away, but then...
Yes. It's a battle held every month 
on the night of the full moon
نعم. إنّها معركة تقام كلّ شهر
في ليلة اكتمال القمر
Ja. Um die einzige Magierin der Welt,
die Magierin von Princeps, zu bestimmen,
Sí. Es una batalla hecha cada mes
en la noche de luna llena
Sí. Una batalla mensual
en la noche de luna llena
Oui.
Sì. È una battaglia che si svolge
ogni mese nella notte di luna piena,
Sim. Uma batalha mensal,
realizada na noite de lua cheia,
Битва, проходящая каждый месяц 
в ночь полнолуния