Hideyasu Steve Yanai

February 26, 1928 ~ November 30, 2021 (age 93)


Hideyasu Steve Yanai, age 93, passed away on November 30, 2021. He had a good life, as he often said as he neared the end of it. He enjoyed most of it in excellent health, running marathons through his 60s, riding international bicycle tours through his 80s, and suffering his first heart attack on September 22, 2021. He had a satisfying career–he was most proud of how he mentored and promoted those who worked with him, rather than what he accomplished in developing better products for Rohm & Haas and, towards the end of his career, marketing them in Asia. He was loving and patient and committed to supporting people and causes he cared about, from raising his family in Moorestown to raising the roof at the Japanese House and Garden in Fairmont Park, Philadelphia.

Hideyasu Yanai was born in Tokyo, Japan, on February 26, 1928. He and his two older sisters, Kimie and Seiko, were abandoned by their parents and raised by Lily Cypert, an American missionary from Arkansas. He passed the entrance exam to Tokyo Agricultural College while still in high school, which saved him from the draft. In 1949, as soon as possible after the war (his passport was number 363), he immigrated to the United States, sponsored by Lily Cypert, to attend George Pepperdine University, completing a bachelor's degree from California Polytechnic and a PhD from the University of Minnesota. His friends dubbed him “Steve” in his very first year in the United States, and he made it official when he was naturalized in 1963.

Steve met Esther Vanderwart in Minneapolis, where he was a graduate student and she was a social worker. They were married in 1956, and they were a model of loving kindness, shared values, and mutual support until her death in 2003. He loved babies (Esther didn’t realize he was single when she first met him, because he was usually holding a baby). He persuaded Esther to have babies, named Ruth and Nina, in 1958 and 1960, and he persuaded her to move to Syracuse to help raise Ruth’s baby, Nora, in 1997. This was not easy for Esther, whose passion was to Save the Environment of Moorestown (STEM); Steve, in Moorestown circles, was proud to be known as “Esther’s husband.”

Steve was a visionary and a planner. He gave his analytical chemists early computer components to play with, and they pulled ahead of the curve in automation. He made ambitious vacation plans, years in advance, such as taking his new family to visit Japan in 1966 in conjunction with a scientific conference. Family camping trips were designed to build backpacking skills, culminating in near-encounters with grizzly bears in Glacier National Park in 1973. With Esther, he built a cabin and planted fruit trees on property they donated to Earth Bridge Community Land Trust in Vermont, to keep land in agriculture and out of speculation. Steve and Esther trekked the Himalayas, the Milford Track, and the South Downs Way. They chose Medford Leas, a Continuum of Care Retirement Community, early enough to be on the waiting list for 10 years. 

Steve moved to Medford Leas in 2004, after Esther’s death, where he was known as “that handsome guy who’s never here.” He was exploring Europe on bike tours, living in Tokyo with Ruth and Nora in 2006 and 2012, or attending intergenerational summer camps with Nora. Steve shared his life in his final years at Medford Leas with his last love, Pegi Siegel. 

Steve is survived by his sisters Seiko and Minako and daughter Nina in Japan and by his daughter Ruth, granddaughter Nora, and great granddog Lulu in the USA. He will be missed by many other relatives and friends, including the Saturday morning breakfast group, which he enlivened with origami jumping frogs and the occasional tea bag rocket.

A memorial service celebrating Steve’s life will be held on June 26, 2022, in Moorestown. Please visit for information about services, including a remote option, and subscriptions and contributions to a blog. 

Donations in Steve’s memory can be made to Shofusō, Japan America Society of Greater Philadelphia, which Steve loved and supported. Link here

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Shofusō, Japan America Society of Greater Philadelphia
5070 Parkside Ave., Suite 1404, Philadelphia PA 19131
Tel: 1-267-237-3550

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