Kokkuri-san is very close to Kohina as he takes care of her like a mother. Kohina does not admit it but she actually doesn't want Kokkuri-san to leave her alone.
Kokkuri-san is very protective of Kohina as shown when he protects Kohina from Imugami and prevents Kohina from eating her favorite food, cup noodles, because they are made with unhealthy ingredients.
While it is shown that Kohina is repulsed by Inugami's antics. The pair are seen together often in the manga, doing comical actions such as raiding the fridge together just when Kokkuri-san restocked. Kohina finds use in Inugami and does use him often, however, Kohina was saddened when the three left her alone in the last chapter of the manga. When they came back however, she quickly displayed disgust and tells them to leave right away.
Shigaraki takes the form of an "adult-version" of Kohina who is muscular and often tricks Kokkuri-san to give him money.
Towards the end of the manga, Shigaraki is shown to be the one who was maintaining the "illusion" of Kohina and the two other spirits living with her.
He seems to also value Kohina as he gives his share of beef to her in one chapter, when Kohina claims that she's never eaten beef before.
Tengu approached Kohina first just to obtain information about a young boy that he spotted and came to like, who was Yamamoto-kun.
Later, Tengu removed his mask to reveal a tengu's famous face which is known to be very beautiful to which KOhina scoffs and says "boring".
Later that chapter, Tengu says that "I guess lolis aren't bad either."