Sengoku Youko: Senma Konton-hen

The world is divided into two parts one for humans and the other one for monsters. The world of Monsters is known as Katawara and has many evil powers that wanna kill humans and turn them into monsters. Tama is a warrior and she wants to protect humans from this evil because she loves humans. Her brother hates humans but is with his sister all the time. They met with a swordsman and he was mad and wanted all humans to die and turn into monsters. Tama fights aginst him and no matter who is after him without caring for her, she just wants to save humans from evil. This will begin a war between them.