Battle Girls

The game stars and takes the viewpoint from a female ninja who is said to be one of Japan's greatest warriors. She's part of an elite ninja squad called Anti-Demon Ninja that fights in the name of justice. The main enemy in this story is the OFA (Oboro Forbearance Army) lead by another female ninja who is also said to be one of the finest in the land. These two female ninjas go at it until one of them is captured and trained/transformed against their will into a sex slave.

It's important to note here that the game takes place around 2050 in Tokyo, so technology has become relatively advanced. The world itself seems to be VERY grim. It's also slightly fantasy based as it seems many different races inhabit the world, including vampires, orcs, and various types of evil spirits, which are the demons or "evil influenced" people that are making the world so corrupt. The ninjas also have special, beyond human, abilities as well.

In the year 2049, mechanized robots commonly called GEAR were developed for military application. Since then, their versatile functionality has led them to not only become commonplace in commercial use, but also spawned an entire sports entertainment industry. The prevalent use and popularity of GEARs has created a new academic field known as “Cenorobotics”.

Due to unforeseeable circumstances, the protagonist finds himself transferring to ACE Academy, a premier school for Cenorobotics studies in Japan. He struggles to find a team willing to accept him and his outdated “American” GEAR to compete in the intramural tournament.

Kawakami City is famous for its strong dedication to its samurai ancestors. A strong fighting spirit is always valued and it's even an important factor in succeeding in school there.
Yamato, a second year student from Kawakami Highchool is always with his close friends (4 boys and 3 girls). They have known each other since they were young and have done loads of things together. They have many other friends, but this seven people is a close-knit group, they even have a secret base where they meet...
With the new semester, they welcome two girls into their group and shortly after things start to change...

Prepare for a demon-slaying tale heretofore untold!
She is Taimanin, clad in shadow... The so-called "Crimson Princess Annihilator"...
A half-vampire burdened by a destiny of blood and darkness,
she fights daily to extinguish evil---
Her name is Kurenai.

9-nine- Episode 4 is the fourth volume in a series of supernatural mystery games, with Episode 4 telling a story centered around Noa Yuuki. The entries in the the 9-nine- series share the same setting and world, but each entry focuses on a different heroine. The villainous mastermind is revealed, friends are at odds, the mystery of the Artifacts uncovered, and bonds are tightened through mutual trust. What lies in store for this young man and woman with the power of justice at their fingertips in this installment?