When Takijiri arrived in Osaka, Saburo immediately gave him his instructions.

"I've purchased a house in a place called Shinmeicho. I've even sent a futon, so please go back to Tokyo right away. Koji Nakamatsu will be the manager in Tokyo, so get your instructions from him." Based on Takijiri's reports, Saburo had already been getting ready to expand into Tokyo with the help of the Fujii family, who were promoting Ryukakusan, and other groups.

In January, 1947, Nakamatsu took up his new post. He had joined Kobayashi Daiyakubo in January 1946 by introduction from an acquaintance. He had experience before the war working in Nihonbashi, Tokyo at a wholesaler of cotton, and so had sales experience in Tokyo, which was rare in Daiyakubo. Saburo was also hiring other staff for expansion into Tokyo. Nakamatsu's first task was to establish the new company, Tokyo Kobayashi Daiyakubo. There were proposals for a branch office instead of a subsidiary, but Nakamatsu pushed strongly to establish a separate company. There were several reasons. Commercial law in Tokyo and Osaka was subtly different, and there was a strong wariness between merchants in Tokyo and Osaka. It would be much easier to do business as a different company. Saburo considered the opinion of his elder, and decided to establish the new company.

Unlike today, under the American occupation there were many regulations regarding establishing a company. It was simple if capital was under 200,000 yen, but above that, permission from the presiding authorities was required. Saburo and Nakamatsu, with their capital of 250,000 yen, first had to get past this hurdle. Nakamatsu suggested that it would be easiest to just reduce the starting capital to get registered, but Saburo stubbornly refused to give up. "We have to start with 250,000 yen!" When encountering difficulty, Saburo got more stubborn, and this time was no different.

Finally, six months later, "Tokyo Kobayashi Daiyakubo K. K." was registered. The founding members were Saburo Kobayashi, Kichitaro Kobayashi, Nakamatsu, and six other members. The line-up decided at the founders' general meeting was: President: Saburo Kobayashi, Managing Director: Mitsuji Nakamatsu, Directors: Toru Takijiri, Muneji Kobayashi (President of Nagoya Kobayashi Daiyakubo), and Katsuro Kato (Nagoya Kobayashi Daiyakubo), and Auditors Benjiro Shichijo (Osaka Kobayashi Daiyakubo), and Matsusaburo Oshima (Nagoya Kobayashi Daiyakubo).

Tokyo Kobayashi Daiyakubo started with five people, including Nakamatsu, Takijiri and others sent from Osaka. They were brimming with confidence, but lacking in clients, products, or trusting customers. Everyday, they went door-to-door, visiting each drug store. Tokyo drug store owners openly expressed their wariness upon hearing that it was an Osaka wholesaler. Tokyo residents had long harbored almost instinctual fear for Osaka region merchants. Feelings of fear for differences in culture and livelihood, energy and sensibilities were very strong. Some shop owners even pointed out that in the confusion of the great Kanto Earthquake some 20 years earlier, some Osaka merchants greedily made exorbitant profits. Some owners threw out merchandise placed in the store, or retreated into their shops without even hearing what they had to say. Some employees even had purifying salt thrown on them. It also took them several months to realize how their Osaka accent rubbed the Tokyo residents the wrong way. Saburo went up to Tokyo once a month to talk to the employees about company direction, and about sales, and other things. Starting with Nakamatsu, all of the employees were stirred up by Saburo's endless passion for the work.

Little-by-little with Saburo at the lead, the members' enthusiasm centering on Nakamatsu, and the Daiyakubo tradition of never letting down their clients and customers, even the Tokyo Pharmacy owners came to understand. Their client-base grew, and through their introductions, their accounts also grew. Unlike the Tokyo wholesalers, the Daiyakubo business style and the thoroughness with which they looked after their clients and customers took root in Tokyo surprisingly quickly.

Tokyo Kobayashi Daiyakubo was making a profit in 1948, only a year from starting business.