Lady Chiyoko Sakai is Jin's mother, the wife of Kazumasa Sakai and Lord Shimura's sister. She died of illness when Jin was seven. She never appears on screen, but she shapes Jin and his father, and a bird in the open world stands for her.
Chiyoko is the link between Clan Sakai and Clan Shimura, which is why Shimura is Jin's uncle. After she died, the servant Yuriko helped raise Jin and look after Kazumasa.
Golden songbirds lead Jin to points of interest, the way the Guiding Wind stands for his father. The fox and Inari story ties her to the Inari Shrines you find across the island. She is mentioned again in the Iki Island story when Kazumasa remembers her.
Baku the Voiceless
Baku the Voiceless is a silent vendor who appears only in New Game+. You find him on the small island at the centre of Lake Izuhara, in Ariake. He sells armour, dyes, charms, hats and masks for Ghost Flowers.
Bataar
Bataar is the Mongol general behind the attack on Komatsu Forge. Jin and Yuna fight him while defending the forge in Hammer and Forge.
Bettomaru
Bettomaru is the master of the Way of the Flame who lives in a dojo at the top of Mount Jogaku. You climb through a snowstorm to duel him in the Mythic Tale The Undying Flame, and he teaches Jin the technique during the fight.
Black Dye Merchant
The Black Dye Merchant is a hidden vendor in a cave east of Kawamata Village in Kushi, Toyotama. He sells deep black armour dyes and cosmetics for Flowers.