In June, a girl throws herself from her school rooftop. As class president, Shimabara witnessed her death and becomes determined to uncover the truth behind it. Her investigation leads her to Kusamizu Yuusui, a mysterious girl hiding a dark and troubled past. But through another perspective, we discover Yuusui’s connection to the girl who died: a fragile bond shaped by loneliness, bullying, and fleeting moments of warmth. As past and present slowly collide, the truth behind the tragedy begins to emerge.