With Kageyama as her chauffeur, Reiko and her friends visit a crowded summer festival, where a cracked smartphone is discovered. Its owner was poisoned in his apartment, and he died wearing nothing but briefs. Three women the victim dated simultaneously on a matching app fail to match the height of a suspect seen exiting his residence, which leaves Reiko puzzled at the true culprit's identity.

The show’s own verdict is on its page.