Otome Degraman: Act I. Vincent & Cassel DEMO is a game where you will get to know the main characters of the series, which is about a girl who is kidnapped and then has to face various dangers. In the beginning, she will meet two mysterious men who will try to get her to join them. She will have to face many different dangers, such as being in a dangerous place, being attacked by monsters, etc.

The first thing you need to know about Otome Degraman: Act I. Vincent & Cassel DEMO is that this is a visual novel. This means that the gameplay is based on the story, and not the other way around. In other words, you will not play as the main character, but you will be in a place where you have to make decisions, which will lead to different endings. The main character will not have a special power, but you can see her and hear her thoughts. Vincent & Cassel DEMO has many characters, and you can choose to be with one of them. Each of them has a different personality and a different story.