Note that in the Liu family, they place their surname first.
Liu Ein is the third eldest of the siblings, at 21 years old. Clearly the most musically-inclined of the family, he spends most of the day practicing on his guitar and practicing with his band, who no one has ever seen or heard but must assume exists as Ein speaks of them so often (though the name of the band seems to be in constant flux...) A social butterfly only by his dating close to every available female on the ship, Ein will often show up and hover around the background of scenes, looking to perfect his "cool, brooding artist" demeanor.
His roommates, Pander and Zander, don't seem to spend much time in their room.
A few years ago he dyed his hair various shades of purple for no real reason. This seems to be the ultimate truth behind everything that Ein does - he does it because he wants to, because the mood grabs him, because he has no reason (or sometimes, every reason) not to. Exactly why Elysium lets him stay on considering he doesn't do any actual work is a mystery, though it's rumored that General Tolst has a soft spot for starving rock bands...