Quality: Used, Like New Size: 110 (JP), 5-6 years old (US) Material: Linen What is a Jinbei? Jinbei are pajama-like clothes that Japanese people wear during the summer – you’ll often see locals sporting them at festivals, such as summer firework shows. Consisting of a light and airy kimono-style top and loose short pants, jinbei were traditionally the sole preserve of Japanese males, but have become more unisex in recent years.