By A.D. 2010, all men have died off quickly due to a dramatic change in the environment and an unknown contaminant. The population decreased to the lowest number ever seen...until only the women were left alive. They live huddled in small corners of a world mostly reclaimed by nature. There are those who accept their inevitable extinction and live a carefree life... There are those who try to continue on the race with the help of science... It is a society of constant conflict over their differences of principles and policies. The story takes place in the center of Tokyo. It is one of the places left for them. The conflict over the specimen of ICE and the chance it may provide to save humanity begins. (Source: AnimeNfo)

Music video for Namie Amuro's B Who I Want 2 B, a track from her album Genic, featuring Hatsune Miku.

In a world overtaken by war and conflict, Hypnosis Microphones—devices through which a user channels lyrics that can affect the listener's brain and even cause physical damage—were introduced to the masses by the Party of Words. Revolutionizing warfare, Hypnosis Mics have transformed words and music into the sole weapons used by gangsters, terrorists, and the military, with physical weapons having been banned from use. As a result of swooping in during the chaos, the all-female Party of Words rules over the Japanese government. Women in Japan now live in Chuuouku, while men battle over surrounding territories outside the ward through rap battles. With intentions unknown, the Party of Words begins to gather the former members of the now-disbanded legendary rap crew The Dirty Dawg to fight not for territory or war, but for their respective crew's pride and honor in the greatest rap battle of all time. The first Division Rap Battle is about to commence, and practice is not something these rappers are going to need.

Dreaming of changing the world for good, Akuto Sai transfers to Constant Magic Academy where he befriends a virtuous ninja clan member, Junko Hattori. On the way to the academy, they vow to make the world a better place together; however, the situation suddenly takes a turn for the worse upon his arrival—it is prophesied that he will become the Demon King! As word of his destiny spreads, the school begins to fear him, and Junko's trust in him falters. While Akuto is determined to not let his predicted future control his fate, it seems as though everything he says and does only serve to reinforce the fact that he is destined to be the Demon King. Moreover, he is surrounded by a harem of beautiful girls who each have their own plans for him, ranging from bringing him to justice to simply showering him with love. With his newly awakened powers, Akuto must cope with his constantly growing list of misfortunes and fight to prove that his fate is not set in stone.