Flags of Japanese prefectures
Each modern Japanese prefecture has a unique flag, most often a bicolour, geometric, highly stylised design, and often incorporating the characters of the Japanese writing system and resembling minimalistic company logos. The heraldic badges worn by warriors in medieval Japan (mon) were forerunners of the modern emblems used in the prefectural flags.
Source: Wikipedia — Flags of Japanese prefectures (CC BY-SA 4.0)