Hayasaka Koumi (早坂香美) is a Japanese pop singer and idol managed by Step one. She is a member of the avex trax group callme and formerly a member of the group Dorothy Little Happy. She was originally a back-dancer for DLH before becoming a permanent member in November 2010, and she graduated the group in July 2015.
- Stage Name: KOUMI (コウミ)
- Birth Name: Hayasaka Koumi (早坂香美)
- Birth Date: May 31, 1996
- Blood Type: O
- Birth Place: Sendai, Miyagi Prefecture