A male Catholic priest exorcist who was repelled from the church because of his methods, he used to be both Mikamis' (mother and daughter) mentor, 45 years old. He is said to be one of the best and most powerful exorcists currently active thanks to his training on Myoushinzan, but with the progressing story, he becomes more like an advisor than a ghost sweeper. In one point of the manga it is suggested that he will become the chairman of the GS community one day.

You say you got a ghost in your prefecture? In Japan that means you need to call Ghost Sweeper Mikami, the paranormal detective agency that's a little abnormal. Okay, make that a LOT abnormal, but they DO specialize in disposing of things that most people don't even believe exist. Run by the visually delicious and even more avaricious Reiko Mikami, and aided by the very perverted (but also very loyal) Tadao Yokoshima, they'll take any case that pays. And Tadao will do anything that might let him sneak a peek at Reiko's magnificent physique. How unfortunate for him that Reiko basically sees him as cannon-fodder, something that's quite useful when your day to day business involves exorcising oni, yurei, yokai and anything else you might find in The Illustrated Bag of One Hundred Random Ghosts. 
 
(Source: Sentai Filmworks)

He was a veteran seiyuu born in Chiba Prefecture.  He retired from voice acting on December 31st, 2000 when he felt a weakness in his own voice. Sogabe died on September 17th, 2006 at around 8 PM from esophageal cancer, with which he had been diagnosed two months before.

Overdevelopment and crowding in Japan has forced many of its indigenous spirits and ghosts to lose their homes. Due to problems caused by the homeless spirits, a new profession was created, the Ghost Sweepers (GS). Private exorcists for hire; they serve only the highest bidder to survive in the cutthroat corporate world. Among this, the Mikami GS Company, led by Reiko Mikami and her two assistants, the teenage boy Tadao Yokoshima and the ghost girl Okinu, is said to be the best. 
(Source: Wikipedia) 
Included one-shot: 
Volume 1: Gokuraku Mouja (Ghost Sweeping in the Haunted Mansion)

Got some time?

Kazuhiro Karasu