I'm assuming you're referring to the popular manga and anime series "Attack on Titan" (also known as "Shingeki no Kyojin" in Japanese). The series, created by Hajime Isayama, is known for its dark and suspenseful storytelling, set in a world where humans are under attack by giant humanoid creatures known as Titans.
Standing in the hallway was a woman who looked exactly like him—same scar on the jaw, same tired eyes, but sharper. More complete. She wore an ATK lab coat with the nameplate: atk girlfriends full
She was taller, with fiery red hair and a tactical harness over a cocktail dress. Kaelen’s hand went to his sidearm. I'm assuming you're referring to the popular manga