Chirayu is an avowed proponent of the "sufficiency economy" philosophy that is promoted by King Bhumibol Adulyadej.
Chirayu's father Charunphan Isarangkun Na Ayuthaya was a diplomat, foreign minister, and member of King Bhumibol's Privy Council.
From 1976 to 1979, Chirayu was the dean of the faculty of economics of the government-run National Institute of Development Administration (NIDA).
After he had taken a stand for a controversial tantalum factory in Phuket Province that was burnt down by furious locals who were afraid of hazardous wastes, Chirayu was confronted with allegations of corruption, that could however not been proven.
[3] Later, King Bhumibol appointed him Director-General of the Crown Property Bureau (CPB), that is responsible for administering the immense royal assets.