When Ryder Onopa was a child, a friend came over for a sleepover only to grow unsettled as the hour grew late.

The friend wanted to go home, so Onopa’s mother, local physician Janet Onopa, grabbed a copy of “Winnie the Pooh” and read to the boys. When she was done, the friend, now comfortable and secure, decided to stay.

Many years later, as a young medical resident on pediatric rotation, Ryder Onopa would carry with him his own copy of “Winnie the Pooh” to read to hospitalized children in need of their own small measure of comfort and reassurance.

Such empathy and compassion, paired with a keen, incisive intellect, didn’t escape the notice of his peers and supervisors. Onopa, 30, was selected to serve as a chief medical resident in what would have been his final year of his internal medicine residency.

Onopa died of cancer on Friday.

“He had the sweetest soul and could easily be your best friend,” said Dee-Ann Carpenter, an internist and assistant professor with the University of Hawaii’s John A. Burns School of Medicine. “He was genuine and selfless and very real. He was humble.”

Onopa grew up in Maunawili and was a graduate of Punahou School. He earned a bachelor’s degree in applied mathematics and biochemistry at Columbia University and spent a year doing research at a diabetes lab at New York University before returning home to attend medical school.

He graduated from JABSOM in 2014, having earned the prestigious Friends of the Medical School Aequanimitas No‘ono‘o Pono Award and inclusion in the Gold Humanism Honor Society.

William Haning, a UH psychiatry professor and former director of undergraduate medical education at JABSOM, remembered Onopa as a “kaleidoscopic personality,” a student whose obvious intellect and affability were balanced by natural human frailties that made him relatable to the patients he treated.

Haning recalled working with Onopa during the notoriously difficult brain and behavior study rotation, during which students assumed responsibility for reporting on learning issues related to patient cases.

“(Onopa) was known for giving the most comprehensive presentations,” Haning said. “He put so much work into them and they were brilliantly organized. He had an appetite for the material and he was voracious. He was never satisfied with anything at the buffet table.”

Haning noted Onopa’s lineage of outstanding medical practitioners, including his mother, who once served as medical director for Queen Emma Clinic, and his uncle Stephen Kemble, a noted psychiatrist. Onopa’s grandmother, Virginia Fine, was also a clinical psychologist.

“They provided a family tradition against which Ryder would be held to high account,” he said. “And he was well on his way to fulfilling that.”

Janet Onopa said her son was “an incredibly easy kid, always whip smart and incredibly verbal and always extremely kindhearted and inclusive.”

“He could be friends with anybody because he was very good at listening. He was everybody’s confidant.”

Such qualities were only magnified during his experiences as a medical student and resident, particularly as he turned his focus from oncology to pain and palliative care.

“He was an incredibly good physician,” Janet Onopa said. “He was exceptional in his ability to connect and offer empathy. Ryder knew how to talk to people about horrible things and make them less horrible.”

Onopa earned many honors as a resident, including the 2016 Golden Crab Award, for excellence in the study and practice of oncology; 2017 upper-level resident of the year; and The Queen’s Medical Center Outstanding Resident Award for 2017.

Carpenter, Onopa’s day-to-day supervisor as a medical resident, noted Onopa’s keen interest in improving Native Hawaiian health. Onopa performed volunteer work on behalf of the Department of Native Hawaiian Health at Lau Ola Clinic and Papakolea Hawaiian Homestead Community Center.

Onopa also bore the strong influence of his father, author and retired University of Hawaii English professor Robert Onopa, including a passion for the outdoors, a love of classic science fiction and a mind for philosophy, particularly Greek stoicism.

An avid hiker and nature photographer, Ryder Onopa was eager to share his passions with friends and colleagues.

“We spent hours recycling the same six hikes along the Koolau mountain range, walking barefoot in streams with his dogs, and constantly eating,” said close friend and classmate Lauren Oshima.

“He would excitedly show me, and honestly everyone, the small loi he created in the stream down below his house. He would constantly walk ahead during a hike to capture beautiful images, which he always shared with everyone later. During these moments, I witnessed his mind-boggling intellect, sincere curiosity in the world around him, never-ending humor and wit, genuine kindness towards all living things, refreshing idealism and consistent desire to make the world a better place.”

High school and medical school classmate Kendra Dilcher Johnson recalled Onopa as “always up for an adventure, whether it be climbing up slippery waterfalls or trying to learn every cranial nerve in an anatomy lab together.”

Onopa is survived by his parents, Janet and Robert, and brother, Alex.