Firefly Wedding manga volume 4 features story and art by Oreco Tachibana.

Satoko's bodyguard, Kotaro, comes to her rescue at last, but Satoko can't quite bring herself to celebrate. If she leaves now, it means saying goodbye to Shinpei, the assassin who has saved her life time and time again. Making matters worse, seeing Satoko with Kotaro ignites a fierce jealousy in Shinpei that drives him to challenge Kotaro to an explosive showdown! As the two men clash, the truth behind Satoko's kidnapper comes to light.