Sakurako-san no Ashimoto ni wa Shitai ga Umatteiru S01E06 - Asahi Bridge Irregulars

While at a summer festival, Kougami is separated from her friends. She happens to catch sight of a woman standing on the bridge. Clad all in black, there is something off about her... As Kougami suspects imminent suicide, the woman vanishes, leaving an ominous letter and a diamond ring behind. Determined to prevent her death, Kougami asks Isozaki and Utsumi to help her find the woman...