“Firework” is the title track of the group’s second EP, “First Howling: We.” The song describes a love-story set in summer when the group finds “you”, shifting the story from “me” to “we"—as noted by the change in EP name between the first and current release.

The song highlights the emotions between the singers and “you” (the listener), which are difficult to contain yet explode brightly and are vivid like a firework.