- Yumi briefly blushes and looked comfortable when Ami hugged her in "Collect All 5!". She looked as if she felt in love with her, with little flowers appearing in the background.
- The duo hugged a lot for a pair of best friends in the first season, though it was slightly toned down by the second season.
- There are two◊ storyboards◊ that were from the show's production blog (now closed down), both showing Ami and Yumi actually kissing, in front of a confused Kaz. It's generally accepted that these were meant as an in-joke in response to the real-life duo viewing their cartoon counterparts as this, considering that same-sex kissing (and couples) in kids' shows would still be a point of contention even by the end of The New '10s.
- Yumi carried Ami in a somewhat romantic way in one episode.
- This happened again, this time vice versa in "Camping Caper".
- In "In The Cards", the title characters realize they don't need a guy they had both been pursuing throughout the episode and hug under a rainbow.
- In "Truth Or Dare", Yumi actually touches Ami's butt, only to use her uniform as a tissue for her nose.
- In a brilliant Alien reference in "Dis-Harmony", Harmony suddenly pops out of nowhere from Yumi's heart, with little hearts circling around her head, then saying to Yumi "I'm your number one fan!".
- In the same episode, earlier while in a photo booth, Yumi smiles upon being licked by Harmony. Except not when it happens again.
- In "Uninvited", both Ami and Yumi share the same room. Also, in the next scene, their room only has one bed, which means they must share it as well.
Ho Yay / Hi Hi Puffy AmiYumi