Zen Master Ko Bong was Zen Master Seung Sahn's teacher. He became a monk at an early age at Nam Jang Sa, and later attained enlightenment while sitting Kyol Che at Tong Do Sa temple.
Ko Bong Su Nim was renowned for being one of the fiercest keen-eyed masters of his generation, well known for his deep enlightenment and wide actions. He mostly refused to teach Korean monks, calling them arrogant, and preferred only to teach nuns and laypeople. Until he met Seung Sahn Sunim, Zen Master Ko Bong had never given inka or Dharma transmission to any monk.
After getting enlightenment, Seung Sahn Sunim went to check his attainment with Zen Master Ko Bong. Ko Bong Sunim tested him with many difficult Kong-Ans, all of which the young Seung Sahn Sunim passed with ease. Zen Master Ko Bong finally stumped him with the Kong-An "The mouse eats cat food, but the cat bowl is broken." The two sat facing each other, eyes locked, for close to an hour, when suddenly Seung Sahn Sunim had a breakthrough and gave him the correct answer. Zen Master Ko Bong then said "You are the flower and I am the bee" and soon after gave Dharma transmission to the young Seung Sahn Sunim. Ko Bong Sunim spent his final days at Hwa Gye Sa temple in Seoul, being cared for by his only Dharma heir, and eventually he passed away in 1962.