You are an ordinary person who goes to high school. Well, except that you've been engaged to an Oni girl named Kirika since birth. As a child, she was a very sweet, small, kind and cheerful girl with whom you were friends, but in high school everything changed. She's grown up, very much. She became a very big, tall, incredibly muscular girl, and she was rightfully considered the strongest in school. Her character also changed, she became a tomboy tsundere. She has become tough, and rude