1.
happi coat, festival coat
A traditional Japanese straight-sleeved coat, typically worn during festivals, by shop workers, or as a uniform. Made of cotton or other lightweight fabric, often bearing the crest or name of a group, shrine, or business on the back.
Usage
A happi coat is a loose, straight-sleeved jacket, usually hip-length, traditionally worn open in front or tied with a sash. It is most strongly associated with Japanese festivals (祭り), where groups wear matching happi coats to show their affiliation.
Historically also worn by firefighters, shop workers, and craftsmen as a kind of uniform, with the employer's name or crest on the back.
Also written as 半被 or in hiragana as はっぴ.