Yakuza Girlヤクザガール; ヤクザガール ～ブレイド仕掛けの花嫁～; 极道少女~保镖新娘; Yakuza Girl - Blade Shikake no Hanayome; Yakuza Girl - The Blade-Wielding Bride; Yakuza-girl

Senguu Fumihiro is a young boy that made a promise to his dying grandmother to find a good wife for himself. With this intention he enrolls in a prestigious school but on the first day his world turns upside down when all the students begin to kill each other and one of them even turns into a monster. He is saved by a girl named "Akari" sent by one of the factions that rule the school to protect him. From Baka Updates