On first hearing, an exhibition consisting largely of variations on the Kanji character , the number one (pronounced ichi), sounds like it might be, well, a tad minimalist. But Yusaku Tawara's "one" is anything but a simple concept. Each rendering is truly a work of art that rewards lengthy contemplation and repeated views.

Hado -- meaning a wavelike movement, or fluctuation -- was a word Tawara favored to describe what he perceived as the fundamental element of both natural and spiritual phenomena. In his way he treaded a path similar to that of thinkers who in recent decades have sought to find common ground between Eastern philosophy and modern science, a la the "Tao of physics." And indeed, Buddhism was a powerful influence on Tawara's life and art.

Born in Onomichi, Hiroshima Prefecture, Tawara showed artistic promise at an early age and apprenticed himself to Western-style painter Wasaku Kobayashi while in high school. Entering university in Tokyo, he dropped out to concentrate on art after an oil of his won the Prime Minister's Prize in a competition. That was in 1951; for the next decade he devoted himself to painting oils like the intense, thickly slathered Still Life from 1957, which juxtaposes a fish and a pear in spare Zenlike fashion.

Then, in 1963, he abruptly quit painting, for reasons he never explained. For 25 years he worked at Bingoya, a folkcraft shop he ran with his brother in Tokyo, and earned a reputation as a collector and curator of traditional crafts, particularly clay dolls. Along the way he became close to textile designer Keisuke Serizawa and other members of the Mingei folk-arts movement.

In 1987, Tawara resumed painting -- but this time with sumi ink, not oil. During the final decade of his life he was astoundingly prolific in this medium. One year he devoted himself to producing ten tiny postcard-size sumi works a day, for a total of 3,650, many of which he mailed to family and friends. A few dozen of these are on display at the Nerima.

During this period and posthumously, Tawara gained more recognition overseas than he did at home, beginning with an exhibition in London in 2000. In 2012, eight years after his death, the Indianapolis Museum of Art produced his U.S. debut, Universe Is Flux: The Art of Tawara Yusaku, which went on to the Asia Society in Houston in 2013. The current presentation is essentially the same show -- the first major exhibition of the artist's work in his home country.

Though Tawara's late-period output was prodigious, it is not the quantity but the quality of his work that inspires awe. Every painting, large or small, offers food for thought, and a bit of an epiphany. His Buddhist motifs range from a series of purely abstract images titled "Nirvana" to mandalas that display arrays of cloudlike brushstrokes in place of Buddha figures. The cloud motif, which he referred to as "auspicious clouds" (zuiun), is really a more rounded variant of his "one" stroke: a single, elliptical, counterclockwise swipe of the brush that trails off to the bottom right, looking a bit like the capital letter Q, or perhaps a tadpole. He was also fond of waterfalls, mountains, and ocean waves, drawing inspiration from the Song-dynasty masters of sumi landscape art. But these nature-evoking images so brilliantly straddle the spectrum between figurative and abstract that they become a sort of Rorschach test of our own aesthetic inclinations.