Normally, on your first trip to Sei-an Aristocratic, you must pass through Rao's building. During this, you must talk with Rao several times and agree to help her retrieve her Prayer Slips and the Fox Rods. This can be skipped by jumping over the wall to the East of her building.
One side effect of performing Rao Skip is that the trigger which normally blocks Ammy from running right through the back entrance is never removed. This means that you must perform Rao Skip every single time you wish to pass from the bridge area to the main area of Aristrocratic. This also means that one can trigger Rao's "Wait!" dialogue even after she disappears when revealed to be Evil Rao.
It is relatively simple to KT over the invisible wall.
In order to clear the invisible wall, one must perform a somewhat precise gold dash double jump from the deck surrounding the entrance to Rao's building. Dashing toward the right, jump just before hitting the fence, then double jump to get over the invisible wall and onto the actual wall. If you jump too early, you will hit the roof and lose all speed. If you jump too late, you will not have the height to make it over the wall.
It is possible to clear the invisible wall, but not make it onto the physical wall. If this happens, one can jump, wall jump off the invisible wall (holding left), and air tackle bounce off the invisible wall to land on the physical wall.
Once on the physical wall, Ammy may begin to vibrate and become trapped, causing the camera to flash rapidly. If this happens, the most reliably method to free Ammy is to repeatedly tap up on the analogue stick until she is freed. There is a possibility she will fall through the physical wall, in which case you can jump left to get in position to get back onto the physical wall using the invisible wall, as described above. If you jump while Ammy is vibrating, there is a very high chance she will fall through.
Once Ammy is stable on the physical wall, jump to the right and forward to fall into the main Aristocratic area.
It is also possible air tackle over both walls and land directly in the main area, though this is very precise: https://youtu.be/zQTo9fK0k-A?t=11