MARS, Volume 4

When old friends of Rei show up at the school fair, Kira finds that she may have some heated competition for his love. His old flame, Shiori, confesses that she never gave up loving Rei, and she now wants him back. To make things worse, Kira uncovers more about Rei's dark past and his brother's suicide. Would she be better off if she just let Shiori have him?