As Kokamonin Seishi was the daughter of Tadamichi and the older sister of FUJIWARA no Kanezane, Kokamonin no Betto composed poems on occasions related to Kanezane, such as the "Udaijin Kanezane ke uta-awase" (poetry contest sponsored by the Minister of the Right Kanezane) in 1175 and the "Udaijin-ke Hyakushu" (Hundred-Poem Sequence sponsored by the Minister of the Right's family) in 1178.
皇嘉門院聖子が忠通の子で藤原兼実の姉であることから、1175年（安元元年）の『右大臣兼実家歌合』や1178年（治承2年）の『右大臣家百首』など、兼実に関係する歌の場に歌を残している。