Flagger no Houteishiki

A high school student named Ryoichi Toujou leads an ordinary life until he is chosen as the debugger for a system called "Flagger." This system allows users to experience a love-romance anime-like existence. Ryoichi hopes to use it to win the affection of his crush, Satou Keiko. Soon after, his parents leave the country, and unknown girls start living with him. As a result, his relationship with Keiko ends abruptly.