Sin-bound Haibane cannot achieve their "Day of Flight" until they are no longer sin-bound. If they remain sin-bound after a certain amount of time, they cease to be Haibane. The Communicator tells Rakka that these Haibane lose their wings and halos, and are required to live apart from humans and Haibane. (The viewpoint at this moment shifts to the false wings that are a part of the Communicator's uniform and the emblem on his hood resembling a halo, perhaps as a hint that the members of the Haibane Renmei are these "fallen Haibane." It is possible that the Toga, the only people who can enter and leave the city of Glie, originate as fallen Haibane.) Despite this, Reki believed that when her time as a Haibane was over, she would simply vanish if she were still sin-bound. The Communicator tells Reki "You know what happens to a Haibane whose time expires before she becomes ready to take the Flight". This could mean that Reki has seen other sin-bound Haibane expire prematurely before.