The name "Tsukasa" comes from the character for the "Ji" (司) in "Shouji." Tsukasa's real name outside the game is An Shouji.
Subaru has clothing damage and never left the field after the fight in episode 18, which means she wasn't PK-ed and actually won that fight.
Unlike the other more masculine male characters, Tsukasa is a very girly-looking boy, with his clothing including a long skirt that can make you overlook his pants. This foreshadows how his player is actually a girl.
Where does Unison fall if Sora is comatose until the end of the R1 games, and apparently undergoes a memory wipe due to Data Drain, then comes back as Haseo in R2, and doesn't remember any of it until very, very, very late into G.U.?
