|Given Name||礫 (Pebble)|
|True Name||礫 (Stepping Stone)|
|Voice ActorEN||Erika Lenhart|
|Voice ActorJP||Junko Noda|
Kuramori takes her to the temple, where it is discovered that she cannot remember the full details of her dream in the cocoon. At first, the only detail Reki could recall was her having walked down a pebble-laden path alone in darkness. It was also mentioned that her wings are black rather grey because she is Sin-bound. Because of this, Reki is shunned by other Haibane. The Communicator tells Kuramori about a special medicine that she can retrieve from an elderly Snow Scale Tree in the woods.
After Kuramori goes into the woods to retrieve the special medicine for Reki’s wings, she is found collapsed. Kuramori's heath is very delicate and fragile and should not venture into the woods. Nemu blames Reki and says that if Kuramori died it would be Reki's fault. However after Nemu and Reki develop a bond while tending to the ill Kuramori.
Kuramori takes her Day of Flight shortly after this incident, which greatly upsets Reki because Kuramori had promised never to leave her. As a result she runs away from Old Home and goes to the East District where the Abandoned Factory, a co-ed Haibane home, lies. There, she becomes close friends with Hyouko and Midori.
Reki and Hyouko later run off to the Western Woods where they attempt to climb over the wall. Hyouko is badly injured in the attempt while Reki is unscathed. This causes conflict between her and Midori.
Reki then spent the next seven years tormented by nightmares regaling her of her forgotten dream in the cocoon, leaving her bereft of any details when she awakens. With the aid of Rakka, she finally remembers her dream in the thirteenth episode and finds her true self. Initially told her true name was read as "run over" (轢), when she asks Rakka for help and is saved, she discovers that instead it is "Stepping Stone" (礫), for caring for others and giving them the start they needed. She becomes a blessed Haibane and takes her Day of Flight.
- Reki is a former smoker. She stops smoking in the eleventh episode, *Parting*--*Darkness in the Heart*--*Irreplacable Thing*.
- Kuramori gave her the job of tending to the newborn Haibane and the Young Feathers.
- Reki is the one who found Rakka's cocoon in Old Home.
- After her stunt with Hyouko, she was banned from the east district.
- Like Rakka, The Communicator gave her the riddle, "To recognize one's own sin is to have no sin."