A modern ordinary woman who can't be found after being thrown into the crowd accidentally gets a black notebook one day, and is forced to fall into the sea of sisters, aunts, and concubines.
What should I do? A certain woman is just a otaku with no theoretical knowledge and no experience in struggle. Facing the surging craze of struggle, she can only rely on the magic weapon of occasional inspiration - a tattered black notebook. No, now we really have no choice but to fight against the odds.