At an age when some men are compelled to take stock of their lives and make peace with the goals they will leave unfulfilled, Motoharu Watanabe raised his head, blinked his eyes and saw a future delimited in glorious expanses of 26.2 miles.

Watanabe was 53 at the time, a veterinarian with an advanced martial arts background and yen for worthy challenges. His wife, Emi, had a best friend whose father, Bacu Jeung, had run his first marathon at age 70. Watanabe was intrigued.

With the encouragement of Jeung’s wife, Toshiko — “If Bacu can run it, Motoharu-san will have no problems” — Watanabe signed up for the Honolulu Marathon. He finished in 7 hours, 1 minute and 7 seconds.

“What I remember was that I was an invalid for a few days,” Watanabe said. “(I) told myself, ‘Never again will I run another marathon.’”

That was 21 years and 18,313.8 competitive miles ago.

Last month Watanabe, 73, completed his 19th Honolulu Marathon in 5:08:38, placing No. 36 out of 353 in his age group and No. 3,351 out of 10,767 male competitors.

It was his 700th race of at least 26.2 miles, the standard marathon distance.

Watanabe, who splits his time between Hawaii and Japan, was born in Toyonaka in Japan’s Osaka prefecture just three months after the end of the war in the Pacific. To retain ownership of the family property, Watanabe’s parents had to farm their land, a twist of fate that influenced Watanabe’s initial career path.

“As a child I was always around animals, and it was always my interest to heal them when they were sick,” he said.

Watanabe went on to graduate from Tottori University with a degree in veterinary medicine and a minor in pathology.

In his professional life Watanabe frequently visited Honolulu to attend veterinary conventions. He was introduced to Emi on one such visit by a mutual friend who recognized their shared passion for Broadway musicals.

“I have been married to the woman of my dreams,” Watanabe said. “The Japanese believe that with your soul mate, you are bound by a red thread of eternity. Emi is that thread.”

For the past two decades, however, Emi has found the presence of her forever love, well, fleeting.

“He goes to one marathon a week, and if on holidays they have one, he is there and not at home,” she said. “Talk about golf widows? I am a marathon widow! Yet I am thankful for if he is in good health, he can continue his passion for running.”

Watanabe estimates he runs between 40 and 60 marathons a year, including ultramarathons of up to 100 kilometers (62 miles). He’s done all of the major ones — New York, Boston, Chicago, Berlin, London, Tokyo — as well as several in Hawaii, including Kona, Hilo, Maui, Kauai and the old Kilauea Volcano Marathon. His favorite remains Honolulu, but he also has completed the San Francisco Marathon 14 times.

“It is a natural high,” he said.

Watanabe’s near-obsessive tenacity and focus is evident in his other personal pursuits. As a youth he studied judo, eventually rising to the level of fifth-dan black belt. He’s also a professional-level (fourth-dan) practitioner of shogi, a Japanese board game similar to chess.

Watanabe shuttered his veterinary practice years ago to take over his family real estate business. Now semiretired, he has ample time to train every day and pursue marathon adventures around the globe. In October he ran in the Venice marathon, where, beset by a storm, he made his way through ankle-deep water to the finish line.

“I’m going to run as long as life permits me to,” he said. “I hope I will be able to continue running marathons in heaven.”

Reach Michael Tsai at mtsai@staradvertiser.com.