Oreki and Chitanda are exactly as sharp and easy to be around as you remember, which means even a poolside nothing-mystery lands because of how they think together. The mystery itself barely matters, it's an excuse to watch four people exist in summer heat, bored and curious and content. This is fanservice in the truest sense: more time with characters you actually wanted to spend more time with.
Houtarou Oreki's lazy summer day takes an unexpected turn when his sister volunteers him as a lifeguard at the local swimming pool. What should have been a quiet shift becomes anything but when he runs into his Classics Club friends already there. While the group enjoys the water and sunshine, Eru Chitanda spots something odd: a woman wearing a distinctive white accessory on her ear one moment, gone the next. Her curiosity immediately kicks into overdrive, and soon Oreki finds himself pulled into yet another mystery despite his best efforts to relax. What happened to that missing object? The question seems small, almost trivial against the backdrop of a carefree day at the pool, but Chitanda's determination is contagious. As the club members investigate between swimming and snacking, they uncover the simple truth behind the disappearance. It's a lighthearted mystery that feels perfectly at home in summer, balancing the group's natural chemistry with a puzzle worth solving. The stakes are low, the atmosphere is warm, and the answer is closer than anyone expects.