Myther

In the 2nd year of the Enka era, a scientist has invented Myther, a device designed to create the ideal personality. With it, people can become their ideal selves and break away from their weak selves. However, below the surface, Myther Crime—a hidden social issue—has emerged, in which those who abuse Myther suffer from mental collapse and carry out horrific acts of violence. Kyou, a member of the Special Intelligence Agency, directly controlled by the Japanese authorities, works in secret to fight these crimes. All for the sake of loyalty to the authorities...

(Source: Kodansha, translated)