diff --git a/Assets/Scripts/Mechanics/PlayerController.cs b/Assets/Scripts/Mechanics/PlayerController.cs
index cbfccdc..311cef5 100644
--- a/Assets/Scripts/Mechanics/PlayerController.cs
+++ b/Assets/Scripts/Mechanics/PlayerController.cs
@@ -221,6 +221,13 @@ namespace Platformer.Mechanics
             int mask = standingOnPlatform ? baseMask : (baseMask & ~(1 << JUMP_THROUGH_LAYER));
             contactFilter.SetLayerMask(mask);
             contactFilter.useLayerMask = true;
+
+            // BT57 — 진단 (점프 시점·발판 영역만 출력. PD Refresh+Play 후 본 PM Editor.log direct read 의무)
+            if (jump || jumpState == JumpState.PrepareToJump || jumpState == JumpState.Jumping
+                || (jumpState == JumpState.InFlight && Mathf.Abs(velocity.y) > 0.5f))
+            {
+                Debug.Log($"[BT57-DropThrough] state={jumpState} velY={velocity.y:F2} stand={standingOnPlatform} mask16={(mask & (1<<JUMP_THROUGH_LAYER)) != 0} pos={transform.position.y:F2} bounds.min.y={(collider2d!=null?collider2d.bounds.min.y:0):F2}");
+            }
         }
 
         protected override void ComputeVelocity()