In the narrative titled "The Badger," found in his collected works New Flower Gathering, Yosa Busan certainly does describe an interesting emotional journey related to his experience with the badger.
His first emotion is that of feeling spooked. He had just settled down to sleep when he starts hearing an excessive amount of tapping on "the shudders by the veranda" (as cited in Crowley, "Appendix," Haikai Poet Yosa Buson and the Basho Revival, p. 267) He heard at least "twenty or thirty taps," and the sound made his "heart beat faster," showing us that he was feeling spooked by the sound of excessive tapping (p. 267). What spooked him even further is that, when he got up and opened the shutter to see, he saw nothing outside the window.
Next, he and the caretaker form a plan to capture the badger; however, their plan fails, and, again, Buson sees nothing outside of his window. The failure of the plan next leads him to feel angry. When the same thing continues for five nights, he next feels weary and decides he will not be able to stay in the house after all.
His next great emotional change happens the moment he realizes a hunter in the village has killed the badger. He feels sad when he no longer hears the badger, realizing that the badger had actually eased his loneliness and had not been a "nuisance" as he had previously thought. He also feels that he and the badger had "formed a karmic bond" and decides to chant nembutsu to help the badger "achieve Buddhahood" (p. 268).
The haiku he includes at the end of the narrative describes the badger having been transformed into a Buddha in late autumn and captures the hopefulness he feels in the prospect of the badger achieving Buddhahood, and that hopefulness is juxtaposed against his previous sorrow. The hopefulness serves to replace his sorrow and ease his mind.