Born in 1888 (Meiji 21) into a merchant family in Kyoto, he entered the Shōgoin Western Painting Institute at the age of sixteen, studying under Asai Chū. In 1907, he traveled to France and enrolled at the Académie Julian. By 1910, he devoted himself to independent work outside the academy, strongly influenced by Cézanne. Returning to Japan in 1914 (Taishō 3), he presented 44 works produced during his stay in Europe as special entries at the second Nika Exhibition the following year, which drew wide acclaim.

However, upon his return, Yasui struggled to adapt to the differences in models and landscapes available in Japan, leading to a period of stagnation. After a long phase of exploration, in 1931 (Shōwa 6) he completed Landscape on the Outer Bōsō Peninsula (Ohara Museum of Art), arriving at what became known as the “Yasui style,” characterized by forms deformed on the basis of realism and an intellectually composed pictorial structure. He also produced a succession of outstanding portraits.

In 1936, he co-founded the Issuikai. In 1944, he was appointed professor at the Tokyo School of Fine Arts (now Tokyo University of the Arts). Together with his lifelong rival Ryūzaburō Umehara, he helped establish what came to be called the “Umehara–Yasui Era,” a defining period in the history of modern Western-style painting in Japan.