Koga Seicha has some of the deepest roots in the Yame tea world, which in itself is renowned as the tea of choice for gifts for the Tokugawa Shogun. Founded in 1819, Koga Seicha pride themselves in using 200 years worth of development history in conjunction with modern machinery to create high-quality tea.

Koga Seicha is currently headed by ninth-generation president Yoshinobu Koga (古賀善信), a 5th Dan in National Tea Judging. His focus is on high quality tea, no matter what changes they incorporate into a long-standing tradition of tea production.

Tea processing in Yame has changed in reflection of greater national tea trends, and the Kogas are no exception. In 1819, founder Heiroku Koga (古賀平六) began roasting tea and selling to Osaka, where it is extremely popular.

This roasted tea was the forerunner of modern green tea, brownish red in color and similar to houjicha. A short while later, Uji tea craftsmen introduced the Aoisei process of rolling leaves after steaming to create the green tea we enjoy today.

In 1831, Heiroku was one of the first tea producers in Yame (then Yamanaka Town) to adopt this process in Yame, at Koga Seicha. 

In the late showa era, 7th generation tea master Masazen Koga (古賀正善) refined their tea process to meet both changes in consumer taste and tea culture.

He was the first Fukuoka tea master to receive a Medal of Honor (Medal with Yellow Ribbon) from the Japanese government for outstanding contributions to agriculture, thanks to his years of tea development work. 

Yame Region is proud of its top production amount of gyokuro (Highest Quality). As much as 45% of all gyokuro available on Japanese market comes from Yame Region. That is the reason Yame is famous and known as one of the few production places of highest quality green tea in Japan.

Yame Gyokuro won Best Prize in the All Japan Green Tea Competition for 12 consecutive years from 2001 to 2012, as well as in 2014 and 2015. In 2014, Yame Green Tea won Best Prize in the sections of both Green Tea (Middle Grade) and Gyokuro Green Tea (Highest Grade).

In 2007, Yame Green Tea took the all the places from the 1st place to the 26th place in the Gyokuro Competition Section, showing its overwhelming excellence over green teas produced in other regions in Japan.

Improvement, refinement, and quality remain standards for the Koga family, who are currently constructing a new factory next to their main shop in Oku Yame.

Oku Yame, or “deep Yame,” is surrounded by mountains, with bountiful morning mist. The unique climate and soil is said to be the reason for the high quality of this area’s tea.

In this scenery, the 200-year legacy of Koga Seicha continues, with the goal of promoting Japanese tea through constant improvement of traditional practices. 

Koga Seicha tea is JAS Organic Certified, HAACP Certified, and Certified Kosher. In 2018, Koga Seicha’s sencha was featured on the Japanese TV program “The World of Japanese Tea.” They have been recognized for the quality of their tea most recently in 2023, when they were awarded the Ministry of Agriculture, Forestry and Fisheries Award (Sencha).