Thread:SlyCooperFan1/@comment-4254464-20161223172145/@comment-1824272-20161223192757

According to Kono, it's a pressurized suit similar to the ones astronauts use. From Famitsu/December 10, 2015:

The human in the PV is wearing a suit similar to a spacesuit, and at that height she wouldn't be able to endure without it.