The audio aspects of the game, such as the soundtrack and voice acting, enhance the overall gaming experience.

As the protagonist accepts the mission, he's tasked with getting close to the target and gathering information. However, things take a complicated turn when he's forced to interact with the target's beautiful sister.

: "Secret Mission: The Undercover Investigator is Absolutely M Best" is an adult visual novel, which falls under the genre of eroge (erotic game) and bishoujo (beautiful girl) games. The game was developed by the Japanese game developer, Meso, and released on July 23, 2020.

: The game follows the story of a 28-year-old protagonist who works as an insurance investigator. He leads a mundane life until he's approached by a female client who asks him to go undercover to investigate a suspicious individual.

The story explores themes of deception, seduction, and hidden desires as the protagonist navigates his undercover mission while dealing with his own emotions and the charming characters around him.