Bone is lost in pose mode In Object mode, all of finger rigs are visible, but in pose mode, 
I can not see a single finger rig. 
Even if I press ALT + H, I can not see bone. 
If you do not have an easy solution, 
is there a way to create a temporary skeleton?

Here is a .blender file(98mb, download it from Chrome): https://drive.google.com/open?id=12gr2WdT6wYQw2TzCG8IAh1M1zN6jndMp
You need to select your bone in Edit mode, then switch to Pose mode and reactivate the Wireframe option in the Properties panel > Bone > Display