First off  the room is packed with pictures, but at least the the colours match and it looks pretty clean compared to most hardcore otaku rooms. The character this otaku is obsessed with is Feena Fam Earthlight from Yoake Mae yori Ruriiro na;

Yoake Mae yori Ruriiro na (夜明け前より瑠璃色な?, lit. “A brighter blue than that before the dawn”) is a fictional series centering on a princess from a kingdom on the moon who lives with a family on Earth for a time. It began as a Japanese adult visual novel video game developed by August that was first released on September 22, 2005 for the PC, and the PlayStation 2 adaptation developed by Aria was released on December 7, 2006.

The games opening: