Truth: Disorder - Gemini is a strange story about two twin girls: Mei and Aoi. Despite external similarity, their characters are absolute opposites.
Mei is an open and kind girl, as well as an excellent student. She studies in a prestigious academy and has many friends. She loves her little sister very much and is willing to do everything to make her happy.
Aoi, on the contrary, is closed and lonely, and believes she’s not needed anywhere she goes.Suffering from mental disorders, she’s constantly depressed. She communicates only with her sister, always envying her beauty, intelligence, and ability to be friends with people. She is very attached to Mei and considers her to be the only person dear to her; but because of her personality she often quarrels with her.
On one endless day, Mei asks Aoi to walk around the city. During their walk, they meet a female student who studies with Mei named, Kaya. The girl showers them with a bunch of questions and forces herself to tag along with them. Kaya takes Mei’s attention the entire time. Aoi, seeing that Kaya is more interesting to her sister than her, walks behind them and feels lonely.
The flames of rage ignite inside of her. She’s angry at herself, her sister, and the whole world. She blames herself for her weakness and that she cannot offer her sister anything that would make her happy.
From that day on, she decided to change everything, to become stronger. But can she do it with the sinister voice inside of her head? It can consume her and force her to do things she'll regret forever.