Fumie's servant. He does various tasks for her throughout the anime. She calls him Oyaji because he looks like an old man. 

Imagine if the internet was 'projected' over the living world and you interacted with it using a portable device - glasses and visors which connect you to an augmented reality. In 2026, this technology becomes reality... 
 
Yuuko Okonogi moves with her family to Daikoku, home of an ever expanding tech network which makes up the interactive virtual world. Her grandmother runs an agency to investigate missing children who appear to have vanished from the 'real' world and entered the city's Dennou - literally meaning "electric brain" - a term used to differentiate between the virtual and 'real.' 
 
A hacker culture is emerging amongst the children of the city. Yasako is soon introduced to Isako, whose powers for hunting computer viruses known as 'illegals' belie an agenda that might have sinister motives. 
 
(Source: Siren Visual)

Eleven years after the introduction of internet-connected, augmented reality eyeglasses and visors, Y&#363;ko Okonogi moves with her family to Daikoku City, the technological center of the emerging half-virtual world. Y&#363;ko joins her grandmother's "investigation agency" comprised of children equipped with virtual tools and powerful metatags. She quickly crosses paths with Y&#363;ko Amasawa, an expert hacker of the virtual environment, as Amasawa relentlessly seeks to "unlock" the mystery of a computer virus that emerges from an inaccessible corrupted space.
 
(Source: Anime News Network)