The Medical Examiner's Office yesterday ruled the death a suicide, but police had their suspicions early on in their investigation.
"There was no apparent struggle," said Capt. James Brady, commander of the Homicide Division.
The bathroom is about 4-feet by 8-feet with a sink and a shower stall, Brady said. Investigators noted that blood was not splattered around the bathroom, that items on the sink had not been disturbed, and a bath rug was not askew.
Omori inflicted several shallow puncture wounds in his left shoulder and neck areas that indicated hesitation, Brady said. Omori then plunged the knife into the left side of his chest and bled to death in the shower stall, the police captain said.
Omori was last seen alive a little after 3 p.m. when he was leaving the restaurant to go to the storage building, Brady said. He left the restaurant through a second-floor exit that opens to the roof of the kitchen area. An entrance to the storage building is located on the other side of the roof, Brady said.
Investigators will continue to explore the motive for the suicide to get a clearer picture of what happened, Brady said.
Omori had greatly expanded his businesses in recent years.
Along with the Center City eatery and another at 4002 Spruce St., Omori had a sushi takeout operation at Fresh Fields supermarkets in Pennsylvania, Maryland and Massachusetts. He also had a sushi and sake bar at the Ritz-Carlton Hotel until this year, when the hotel became the St. Regis.
Beloved for its sushi, Omori's Center City restaurant was a popular fixture that attracted celebrities such as Phil Collins and Bill Cosby.
Omori lived in the 1400 block of East Butler Pike with his wife Yuko, 42, his daughter Miki, 14, and his son Ken, 13.
David Williamson, 35, a longtime friend of Omori's, said he was flabbergasted by the news of the suicide.
"This man embodied patience and virtue and all that is right," said Williamson, who as a boy of 12 greeted Omori at the airport for Omori's first visit to the United States.
In the mid-1970s, Omori came to study at Beaver College and lived with Williamson's family in Ambler. He worked as a cook and also ran a hot dog stand at 13th and Walnut. He bought the Spruce Street restaurant in the early 1980s and the first Genji was born.
When he opened the Sansom Street restaurant in the mid-1990s, he called that one "Genji II" and the Spruce Street location "Genji I," Williamson said.
He also owned a sandwich shop popular with University of Pennsylvania students at 40th and Spruce. Called Billybob, the shop recently merged with a Chinese food place next door that he partially owned.
Williamson said Omori in recent months had trouble sleeping, but Williamson said he was not aware of any serious financial difficulties.
After being closed Tuesday because of Omori's death, the Genji on Sansom Street reopened for business yesterday evening.