Spoilers Off applies to the Moments subpages. BEWARE OF UNMARKED SPOILERS
The other Guardians being accepting and welcoming to Tadashi, helping him however they can while he adjusts to being a Guardian. The friendship he forms with Jack is also fairly heartwarming.
Decades after the events of the film, Jack still regularly visits Jamie. Thanks to this, Jamie never lost his ability to see the Guardians. This helps Tadashi, as it allows him to get his first believer and gives him hope that Hiro and his friends could see him again.
After one whole story fretting about not being good enough and undeserving of being a Guardian, Tadashi gets to see Hiro's memories about him. He's overwhelmed by the sheer love and awe his sibling had for him since the very beginning.
Little Nozomi asking "that nice fox from the Tea Garden" for help - thus becoming Tadashi's first believer.
Fred complains about his tiredness, so Tadashi in fox form gives him a banana. Fred immediately realizes who the fox truly is and embraces him.
The reunion between Tadashi and Hiro. Enough said.
Tadashi's decision to entrust his hoshi no tama to Hiro. He literally trusts his baby brother with his life.
Tadashi doesn't give up on people. Even on Callaghan. It pays off.
