A bright blue jelly-like organism washed up on a beach in northern Japan's Sendai Bay. At first, it looked like the Portuguese man-of-war, a tropical jellyfish. But scientists found it was different. A Tohoku University student collected it during routine work. Its color and shape were unusual for the area. After detailed study, researchers saw it did not match any known species. DNA tests confirmed it is new, named Physalia mikazuki. This is a nod to Sendai’s crescent moon symbol. Until now, only one Physalia species, P. utriculus, was thought to live in Japan. This new species overlaps with it in range and may have been missed before. The discovery marks the northernmost record for Physalia species. Scientists used ocean current models to trace its path. They believe the Kuroshio Current carried it from warmer southern waters northwards. Changes in currents and rising sea temperatures likely allowed this journey. Researchers caution this does not mean immediate massive changes, but it signals slow shifts in coastal marine life. Physalia mikazuki, like other Physalia, has venomous tentacles that can sting painfully. Scientists urge public awareness as shore sightings often reveal such surprises first. This new species is a striking find showing nature’s quiet changes.