He bought Puna Plantation Hawai‘i, a papaya farm, around the time of the eruption in the Kapoho area of Puna in 1959. Puna Plantation Hawai‘i Ltd became the parent company name for various entities; the most prominent dba bears his name. The store’s name changed to K Taniguchi Store, K. Taniguchi Supermarket and, finally, KTA Super Stores.
The first expansion was in 1939 when the Keawe street store opened in downtown Hilo. Eventually, the company expanded to its present size being a six-store, island wide supermarket chain. The initial store in Waiākea was lost during the 1946 tsunami. KTA opened in Kailua-Kona in 1959, under the banyan tree, just mauka of the Kailua pier. The Pū‘āinakō store, now its flagship store, on the southern outskirts of Hilo opened in 1966.