Uso kara Deta Makoto

When Kensuke Niikura was in the third grade of elementary school, he lied when he introduced himself in a class at his new school, saying that he had a girlfriend named Makoto. For the next four years, until he entered junior high school, Kensuke continued to make up the story of his "imaginary girlfriend." He became a junior in high school. One morning, "Makoto" appears in front of Kensuke in his second year of high school...?!