Manga Kubo-San Doesn't Leave Me Be (A Mob)

He's just a guy who lacks the slightest bit to be completely invisible to other people. He's like a mob from a computer game that nobody cares about. The guy would have continued his gray life if his neighbor did not pay attention to him, who became very playful towards him. She constantly evaluates his behavior and checks how much he really is invisible to society. Then she becomes his heroine at all! Where will this unusual romantic story lead them?