Bullets being fired blindly like rain and hail"Ransha rangeki ame arare", an idiom came from a song themed on The Hitachi Maru Incident.
Later it was parodied as “kansha kangeki ame arare" ("gratitude and appreciation raining like hail") and this modified idiom became far more popular than the original.Hitachi-maru, a ship requisitioned by the Imperial Japanese Army.Yasukuni Hitachi-Maru Memorial Stele