This Yuzheim—and the entire Alpheim situated above it—are absolutely not a true Otherworld. They are a virtual world constructed outside the server, hence the server is likely located somewhere in Tokyo, the capital of Japan, in the real world.
Qiuya and her fellow traveler are using a gaming machine called "supVR" to fully immerse themselves in this world.
Exiting this virtual world is actually quite straightforward. Simply flick the left index and middle fingers downward twice, then press the "LogOut" button on the main menu window that appears.
Or, if you fall asleep here, the machine will automatically disconnect when it detects brainwave changes, causing you to wake up in your bed in the real world in the morning.
However, for some reason, they're currently forced to fight off intense sleepiness and maintain their wakefulness.
Thus, Qiuya steeled herself and formed a fist with her left hand, then smacked the sharp center of her fellow traveler's hair.
