Rui is a new recruit of “Project Nightingale,” an organization that is dedicated to stopping crime in this cyberpunk version of Tokyo. Rui, whose engineering skills were unmatched compared to anyone his age, decided to join the program in order to help bring peace to the city. He is typically tasked with more secretive things, unlike his friend Tsukasa who often goes on big missions. He goes by the code name “Alchemist.”