Broken String

A 17 year old boy Satoshi Tatsuo, have been friends with three females ever since he was born, Azuri Chisaki, Reina Tora, Kazumi Hoshi. His family and theirs has always been so close, because of their mothers that became a group of four back in high school. He liked Reina Tora, the popular girl in school for a long while now, his feelings started when he was only 7 years old, when his freshman year came, he confessed and they ended up dating. Reina made Satoshi happy, he felt as if his life has been complete and there's nothing else he wants but her. But does Reina feel the same way? How will their senior year end?