Flagger no Houteishiki  

Flagger's Equation, フラッガーの方程式

Would you like your life to be similar to that of the main character in a romantic anime? With "Flagger," it's possible! Toujou Ryoichi lived an ordinary high school life without any drama or excitement. One day, he discovered that he was chosen as the debugger tester for a new system called "Flagger." This system could potentially make him the protagonist of his own story and allow him to win over his secret crush, Satou Keiko. However, this came at a cost: Toujou's parents moved out of the country, and mysterious girls began living with him. As a result, his relationship with Keiko became strained.