Koi, Hanabi (恋、花火, Love, Fireworks) is Hatsune Okumura's debut single.

It was released on September 5, 2007, by Avex Trax.

The CD+DVD edition includes the Koi, Hanabi short film starring AAA's Takahiro Nishijima, Mitsuki Tanimura and Kenichi Endō.