This is story related.
At the 10th floor of Ghost Hall Building, Enter the room and go to the right-hand drawer on the desk to find a diagram of the Divine Beasts. Go to the cabinet on the opposite wall with the Buddha statue and open the small door to find a Hazuki family gi and a Tiger stick. Pick up the large blue pot on the shelf between Buddha and the window and you'll find the Phoenix stick inside. The last one is behind the Yin and Yang picture on the wall behind the desk. Take it off the wall and you'll find the Blue Dragon stick inside. If you want to find them there are another few dummy sticks hidden in the room, but you don't need to bother.
Go to the Buddha statue and and, with the use of the diagram from the desk, arrange the sticks in the corresponding holes on his face. This will open a secret room where Yuanda Zhu is.