Jinbei or Jinbee is Japanese-style home wear worn by males and children.
As for the origins of the name, some insist that Jinbei is short for 'Jinbei-haori,' informal summer clothes worn by a man called Jinbei, but the more prevailing theory is that 'Sodenashi-baori' (sleeveless coat) worn by commoners at the end of the Edo period resembled 'warriors' Jinbaori' (sleeveless campaign jacket worn over armor) in shape. According to old people, it became popular as Tsutsusode (kimono with tubular style of sleeve) in the Taisho period. They say it first spread among people in Osaka.
Jinbei is short-cut, has sleeves without tamoto, and is worn with the left side overlapping the right like usual wafuku (Japanese traditional clothes) by tying the right sash attached to the collar and migoro (main panel) on the front side and the left sash under migoro. It is generally worn with a matching pair of breeches today, but it had consisted only of a long joi (jacket) covering the wearer's knees until around 1965.
It is made as hitoe (unlined clothing) in cotton or hemp. It has umanori (slits) at the bottom of both sides. It has short sleeves or three-quarter sleeves in tubular or wide style, and the size of the wrist openings is rather large. The collar is usually 'a flat collar' without a gusset. In order to wear Jinbei, the attached sashes are tied together, and so no belt is required. Both sleeves and migoro are loose-fitting and airy, and so Jinbei can be worn as summer home wear which keeps the wearer cool.