Flag Tate Tokimashita.

The main character, who calls himself a gal game fanatic, uses the knowledge he gained from gal games in the real world. Take advantage of it ~ I dreamed of a popular harem high school life as a love master! "You're an idiot." The words of a childhood friend pierce the protagonist... Reality doesn't work like a game. “I guess I need to flag that first.” You make up your mind and express your feelings to the person you love.