The Girl I Saved on the Train Turned Out to Be My Childhood Friend, Vol. 4 (manga)

Hina refuses to reveal where she goes on the weekends—not even to Ryou. Worried, he decides to tail her, but what Ryou finds is completely unexpected— Hina is training to become an actress! Though he agrees to cheer her on as she makes her stage debut, Ryou can’t shake the feeling that his childhood friend is poised to ascend to heights he’ll never be able to reach…