Tsuyu

Tsuyu is unusual even among Noragami's cast of spirits: she is the soul of a plum tree, not a shinki and never human, who has stayed at Tenjin's side as his guidepost for over a thousand years out of what the story frames as lasting devotion. She was already present, in this form, when Tenjin himself was young — which places her among the oldest recurring characters in the series by a wide margin.

Lacking human emotion in the usual sense leaves her permanently calm and level-headed, even when Tenjin went through a violent, difficult period in his early history; she stayed loyal to him regardless. Her manner of speech is deliberately archaic and poetic, setting her apart from the more casually-spoken shinki around her, and she has taken on something of a mentoring role toward younger spirits in Tenjin's circle.