391 I'm only waiting for you

"The Celestial domain is in the sky, and the only way to enter the Celestial domain is through a terrifying skyward sea current. The sea current is in a dead sea, and only by using the current's skyward flow would one be able to enter the Celestial domain. The existence of the Celestial domain is a secret unknown to the inhabitants of this world. But to human trial-takers like us, there have been people who have already discovered the existence of the Celestial domain over countless exploratory trials. There have been people who have done deep research on the Celestial domain's location and method of entry."