Rei Riku, Gin no Guardian Wiki

Its possible that she has some relation or connection to "The Collector", due the exact resemblance between the two of them and the fact they share the same voice actress; possibly even being the same person.

Suigin Riku, Gin no Guardian Wiki

Gin no Guardian 2 (The Silver Guardian 2) Preview & Screenshots Are Ready for Episode 3!

Gin no Guardian, Wiki

Suigin Gets Closer to Riku Rei!

Riku Rei - Gin no Guardian - Zerochan Anime Image Board

Spring 2017 Anime: Gin no Guardian The Indonesian Anime Times by KAORI Nusantara

Anime by BLADE

List of Rin-ne chapters - Wikipedia

Gin no Guardian (The Silver Guardian)