Volume 4 of the DARLING in the FRANXX (ダーリン・イン・ザ・フランキス, Dārin In Za Furankisu) manga series was released on February 4, 2019.
List of Chapters
Strelizia strikes the Klaxosaur with one hit and seemingly kills it before Hiro collapses and seemingly dies. However the Klaxosaur is still alive and Streliza enters stampede mode. Hiro has visions of a mysterious red skinned girl with red horns. He manages to regain consciousness and sees Zero Two hurting herself to keep fighting, and he wills his illness to subside so he can comfort her. He assures her that he is her partner and he wants to be her wings. They reconnect and Strelizia effortlessly kills the Klaxosaur. Everyone is amazed that Hiro survived his third sortie.
Squad 13 is later awarded a trip to the beach. During which, the children become curious of kissing and love, and the boys seek answers from Hiro. Kokoro and Mitsuru discover an abandoned modern city. After dinner, Ichigo and Hiro watch a meteor shower and she kisses him.