Born on 3 December 1942, at Sitio Bobaongon, Barangay Mabini, Mainit, Surigao del Norte, on the feast day of St. Francis Xavier and Sta. Hilaria. He was named after the latter. He was born on the hinterlands of Surigao after the family fled the poblacion from the Japanese occupation at the height of World War II.

He coined the names of some of his godfathers and composed his to be Hilarionito Mentalbouni Fukusima Simchico dela Mosende. He, however, retained his official name as Hilario. Fukusima was a Japanese Captain. He was asked to be Yonie's godfather so that the family will be protected by the Japanese. It was said that Lt. Francisco Canuto, also known as Tahid, was also his godfather. Canuto was a retired army officer who led a group of natives, locally known as Colorums, and used to ransack towns of Agusan and Surigao. Canuto had high respect of Yonie's father, Vedasto, and so he was also asked to be a godfather.

Yonie finished his elementary with high honors at Mainit Central Elementary School, and his High School at San Nicolas College at the provincial capital, Surigao. He went on to take Mining Engineering at Mapua Institue of Technology in Manila.

He married Magdalena Victoria Alvarez Yap on 18 August 1973 at Baras, Rizal.

He became mayor of his hometown Mainit after the EDSA revolution in 1986.