“Love eventually ends──” Caught up in the words of his junior, Momose Chiyoda, Tsukumo Nonomura finds himself helping the ‘Heartbreak Detective’. Operating from the Mystery Research Club’s room as their base, this unofficial school detective activity investigates the truth behind heartbreaks. Clients, each harboring their own woes of lost love, come to them seeking answers. This is the story of a girl detective who hasn’t experienced love, solving the sweet and bitter story of love’s end.