Sunday was last seen in prison, where he was visited by Yashma from the Interstellar World Corporation and offered a deal.

After that, Sunday joined the express and became a member, as did Caelus. Sunday was curious and tried to behave carefully with the participants of the express, so as not to say or do something wrong. Since Sunday had not yet become a full-fledged member of the express, he did not have his own room. They couldn't put Sunday in the room with Dan hyung, since Dan hyung sleeps in the archive on some kind of shabby blanket. Since March 7, Sunday was not very comfortable to be in, and with Welt, being in the same room was quite uncomfortable and even a little frightening. Sunday was given a choice, either to sleep on boxes in the pantry, maybe in the main hall of the express on sofas, or to live with Caelus in the same room. Since there wasn't much choice, Sunday had to choose Caelus's room, and the Trailblazer himself didn't mind a roommate.

10 minutes later, Sunday was sitting on the edge of Caelus' bed and looking at his room

— "Em..Trailblazer, your room is big enough. Are you comfortable here? This room is much bigger than Dan Hyung's"