Here's some evidence:
* They are constantly seen together: Tiff and Kirby often spend their time together, whether it's playing games, exploring Dream Land, or helping others.
* Tiff is always there for Kirby: When Kirby is in trouble, Tiff is always there to help. She is supportive, encouraging, and always believes in him.
* They share a deep understanding: Tiff seems to understand Kirby even when he can't talk, which shows how close they are.
Overall, it's clear that Tiff loves and cares for Kirby deeply, and they are the best of friends.