Nanase Ren

This will appear to be a very disturbing animation to most. Designs by Murakami Teruaki, published by Soft by Demand (Anime), and based on the eroge by M no Violet.
(Source: Bakunyuu)
Note: There are 2 Nanase Ren OVAs produced totally different studios, but both feature the same character. The other one is the "Kranke Nanase Ren" (夜勤病棟　Kranke　七瀬恋) bit, which is a special for Yakin Byouto
(Source: AniDB)