What is "tenkaippin"

is a Japanese restaurant chain specializing in ramen noodles. The first restaurant was opened in Kyoto by Tsutomu Kimura in 1981. As of December 2014, there are 233 branches in 38 of Japan's prefectures as well as a branch in Hawaii. The chain is often known by its short name . Tenkaippin holds a special promotion every October 1, which they call , playing off of the name of their restaurant and the calendar date.