Tokyo 2020 has signed-up Nippon Life and the Nippon Telegraph and Telephone Corporation (NTT) as sponsors of the Olympic Torch Relay.
Both companies will serve as presenting partners of the Relay - the top tier of sponsorship.
It means they will be able to recruit Torchbearers and use the Torch Relay's emblem in promotional activities.
Car giant Toyota and Coca-Cola had already signed deals to become presenting partners with this sponsorship group now complete.
Tokyo 2020 President Yoshiro Mori said: "We are pleased to welcome Nippon Life and NTT as Tokyo 2020 Olympic Torch Relay presenting partners.
"With the recruitment of these two companies, we now have all four presenting partners on board.
"Their support constitutes the highest level of sponsorship for the Tokyo 2020 Olympic Torch Relay.
"This is the largest number of presenting partners in the history of the Olympic Torch Relay, and I greatly appreciate the support and encouragement of all of them."
Tokyo's flame for the 2020 Olympic Torch Relay will arrive from Greece at Matsushima Airbase in Miyagi a year from tomorrow, and will first be displayed in the three prefectures which were most impacted by the Great East Japan Earthquake in 2011.
The Relay itself will then begin on March 26, 2020 in the disaster-hit region of Fukushima.
It will pass through all 47 prefectures in Japan over 121 days.
"It is a tremendous honour and privilege to participate in the Tokyo 2020 Olympic Torch Relay as a presenting partner," said Hiroshi Shimizu, President of Nippon Life.
"Moreover, we are determined to help make this event a success with record-high numbers of people participating in and experiencing the event, and the Olympic Torch will travel the length and breadth of Japan, uniting all parts of the country."
Jun Sawada, the President of NTT, said: "We intend to make it the most innovative Relay in history through extensive use of the latest telecommunications services.
"We are going to create opportunities for participation by many people to heighten the excitement surrounding the Tokyo 2020 Olympic Torch Relay in all of Japan's 47 prefectural bodies, and strive to assure its success in many other ways."