Fujiwara no Koshi (藤原こう子)

FUJIWARA no Koshi (or Teruko) (947 - June 29, 979) was the first daughter of Kanpaku (chief adviser to the Emperor) FUJIWARA no Kanemichi in the mid-Heian period. Her mother was Princess Shoshi, a daughter of Emperor Daigo's son, Imperial Prince Ariakira (some say that she was a daughter of Emperor Yozei's son, Imperial Prince Motohira). She was Chugu (the second empress) of Emperor Enyu. She was also known as "Horikawa Chugu."

In 972, her father, Kanemichi, took the post of Chancellor. In February 973, she entered Emperor Enyu's court. In April of the same year, she was proclaimed a Nyogo (consort) of Emperor Enyu, and in July, she officially became Chugu. In 977, her father, Kanemichi, died. In 979, she died at the age of thirty-three.

According to "Okagami" (the Great Mirror), she spent her childhood neglected by her father. Partly because she had a good character and partly because Kanemichi had no other suitable daughter, she entered the imperial court at what was then considered the late age of twenty-seven. Although she was twelve years older than her husband, Emperor Enyu, they seemed to have had a good relationship, although they did not have any children and lost a powerful guardian when Koshi's father, Kanemichi, died. She died only six years after she became chugu. Her death created a rivalry between FUJIWARA no Junshi, a daughter of FUJIWARA no Yoritada, and FUJIWARA no Senshi, a daughter of FUJIWARA no Kaneie, both of whom competed for the position of chugu.