The Nazi propaganda minister, Joseph Goebbels, presenting a violin, said to be a Stradivarius, to Nejiko Suwa on February 22, 1943
She was recognized as a violin prodigy by the age of 10.
Her first teacher was Nakajima Tazuruko, but she soon progressed quickly enough to study with his teacher, the Russian violinist Anna Bubnova-Ono. Suwa was introduced to Efrem Zimbalist while on his second Asian tour in 1930. Her performance of Mendelssohn's Violin Concerto in E minor impressed him enough that the meeting made headlines. He recommended that she study abroad and offered his assistance. While she did not take up this offer and continued to remain in Japan for six more years, she did decide to study under another Russian violinist, Alexander Mogilevsky. Went to Belgium (1936) and studied under Chaumont and then under Lucian Kamienski in Paris for six years.
She gave her European debut in the Salle de Chopin there on 15 May 1939. Although World War II broke out several months later, Suwa continued to stay in Paris to further her studies even after the Nazi regime occupied Paris. Nazi Germany and Imperial Japan, at this time, were united by the Tripartite Pact, and this military alliance allowed Suwa's career to flourish: she was allowed to give concerts to wounded German troops to strengthen the alliance.
Suwa was a featured soloist in a concert given by the Berlin Philharmonic under Hans Knappertsbusch in October 1943 and performed to great acclaim. She also continued to travel between German cities giving concerts, but was finally forced to flee Paris in August 1944 when the Allies closed in on the city. She joined Japanese Ambassador Ōshima's entourage in the Japanese Embassy in Berlin in April 1945 before moving with them to Bad Gastein when the war in Europe ended in May.
She was captured in the Austrian Alps with the entire Japanese diplomatic mission to Germany by the Seventh United States Army in May 1945. She and other Japanese nationals were placed on board the liner Santa Rosa, in Le Havre, France, bound for New York. They were briefly sent to Pennsylvania in August to be detained in the Bedford Springs Hotel in the heart of the Allegheny Mountains before being released in November and sent back to Japan.
After the war, she was featured in a benefit concert at the Hollywood Bowl as the "first Japanese musical star to set foot on American soil since the signing of the peace treaty". She also gave numerous concerts in Japan, including one to war criminals at Sugamo Prison in 1952.
After her years of public prominence were over, she released recordings of Bach's Sonatas and Partitas and Beethoven's Kreutzer and Spring sonatas. Suwa died on 6 March 2012 at the age of 92 in her home in Tokyo.