More than words, paintings have the power to move souls. In his day, underprivileged Japanese art students had never had a chance to see high-quality Western paintings. To improve the situation, Kojiro, as a wealthy, famous man, decided to buy Western paintings and bring them back to Japan. He had a plan to build a museum named Kyoraku Bijutsukan ("Sheer Pleasure Fine Arts Pavilion") where everybody could enjoy the art.

During WWI, posters designed to evoke patriotism were seen everywhere in the United States and Europe. Comparing these posters with their significantly less sophisticated counterparts in Japan, Kojiro realized how far behind Japan was in terms of art facilities. He began purchasing paintings by Sir Frank Brangwyn, the creator of the WWI posters. In Japan at that time, magazines were the only available means to see excellent works of art, but the magazines were scarce. For art students to see fine art, they had to travel overseas. How could poor students afford that? Kojiro, moved by a fervent desire to remedy this situation, decided to devote the rest of his life to the collection of outstanding Western paintings. His collection eventually came to more than 10,000 items, and was later named the "Matsukata Collection."

Kojiro had the opportunity to meet the great impressionist painter, Claude Monet, to discuss the purchase of his paintings. It is said that meetings were organized at least twice, and Kojiro bought a total of 34 paintings, but the exact numbers of visits and paintings are unknown. As they met at Monet's home, Kojiro became familiar with the artist’s taste. He always brought with him a bottle of Monet's favorite wine "Napoleon," at which Monet exhibited child-like excitement.

The Great Kanto Earthquake in 1923 seriously jeopardized the construction of the Kyoraku Bijutsukan. Infrastructure in the entire Kanto region was destroyed and the museum plans were halted. The news of the abeyance of the project from Kojiro was a disappointment to Brangwyn. On top of the devastation of the earthquake, the Japanese government was suffering from a trade deficit, and to remedy the situation, a luxury goods customs act imposing duties of up to 100% on goods including paintings was legislated. Because of this new legislation, Kojiro had to return the works he had collected in Europe when they arrived at the Port of Kobe. Tragic incidents did not stop there. A severe worldwide economic depression occurred, severely affecting Kawasaki’s business, and most of Kojiro’s paintings were seized by the Jugo Bank. To make things worse, this was followed by a fire in London which burnt a warehouse housing his paintings there, and the paintings that survived the fire were confiscated as "enemy properties" by the French government. Other masterpieces stored in different parts of the world were also scattered and lost, ruining Kojiro's dream of building the Kyoraku Bijutsukan.

Behind the scenes of the 1951 Peace Conference in San Francisco, Shigeru Yoshida, then prime minister of Japan, requested the French foreign minister to return the Matsukata Collection to Japan. Yoshida spoke passionately to the minister, as if he was an envoy from Kojiro, and the minister apparently responded with a simple "yes." As an essential condition for the return of the works of art, the French government required the Japanese government to build a dedicated art museum for the collection so that the works would not be scattered again. In 1959, a collection of 308 paintings, 63 sculptures and five books were returned to Japan. The Matsukata Collection found its home in the National Museum of Western Art. At the Museum's opening ceremony, Kojiro's eldest daughter, Hanako, on behalf of her father, made an address in French expressing her gratitude. The Matsukata Collection had its origin in Kojiro's desire to collect works of art for underprivileged art students. Forty long years after Kojiro’s vision of building a museum, his dream finally came to fruition, against all odds.