Yuri Maroev is a secret agent and assassin from the Ural Republic sent along with his brother on a mission to Japan. Once in Japan, he meets systems analyst Mashiro Rieru and uses her high-level security access to get top-secret information from the Ministry of Foreign Affairs. His pretense of romance turns into genuine feelings of love, as Rieru falls deeper into the intricacies of Yuri's fateful covert operations.