The story takes place on a small fictional island in Japan called Rokushiki Jima (6 Ceremony/Equation Island). In this island, there is a festival held every year called the Rokushiki Sai where young girls on the island borrow the power of God and fight each other. There are 6 head families on the island, who succeeds individual fighting techniques and manages the festival tournament.
The Day-side scenario is the original part, featuring the visible side of the tournament.
The main character is Rokushiki Nanaki, who’s the new head of the Rokushiki family and the Miko arranging the tournament. She’s irritated because she can’t enter the tournament herself because of her position and tradition. She was so confident about her fighting skills that she was certain that she will win if she participated. She even beat her own parents, but that doesn’t change anything. However, her 4 friend were the participants of this year’s tournament. The girls are put into a cage surrounded by a magical barrier and with the divine power borrowed from God, fights until one loses consciousness.
The new evening side scenario features some of the other family members and the hidden bloody side of the festival.
Other than the 6 major families, the island had 4 sub-families, which were replacements in case something happens to the 6 families. And addition to that, there was a system called the Shadow Sakura Festival, where the 4 family member can challenge the head of the 6 families and can replace them by force.
Misakura Tomoe is the main character of this story. 10 years ago, she was challenged by Toritari Tsubasa, in the Shadow Sakura Festival. Everyone acknowledged Tsubasa’s strength and the battle between Tomoe was held in form of just custom. However, using dirty tactics, 7 year old Tomoe defeated Tsubasa who was 10 years older than her.
Tomoe remained to be the head of her family, but because how she fought was unfitting for the head, her skills were sealed with a magical rope wrapped around her leg by the Rokushiki Miko. Tsubasa’s sister, Toritari Kaina also despised Tomoe, and swore to defeat her in a justified battle.
10 years after that incident, a new Shadow Sakura Festival was taking place. Misakura Tomoe was challenged by all the four sub families.
[Edited from Akihabara Channel]