[3] Nanayakkara's father Rajah was an entrepreneur and founded the automobile industry through Ishara Traders in 1973 which is now regarded as the pioneer in importing reconditioned repaired vehicles from Japan to Sri Lanka.
[4] Ishara at his teenage was sent to Japan for extensive training after his secondary education at Royal College, Colombo 07.
Nanayakkara pursued his career in financial services and started investing in finance companies such as LOLC.
[7][8] In 2019, he eventually toppled Dhammika Perera to become the richest person in Sri Lanka after a Korean bank came forward with interest and intention to buy the LOLC's subsidiary Cambodian microfinance arm for a staggering US$603.4 million.
[9][10][11] His Browns Healthcare was acquired by another business magnate Harry Jayawardena for 1.6 billion in February 2020.