As Tadashi and Elsa are from different series, they have never met in canon. Even though a few Disney crossover video games could have the two cross paths with one another or get them added in the same team, by the player's choice.
Both Elsa and Tadashi are older sibling who lost their parents. The two have placed their siblings' lives over their own. In their own ways, both Tadashi and Elsa set events that allowed Hiro and Anna to prosper. Tadashi's science and Elsa's magic is what allowed them to create and give life to Baymax and Olaf. Elsa has used her magic to make it snow inside for her sister before she lost control of her magic until Anna helps Elsa with them, while Tadashi had gone through something with the unique snow machine he invented. Since both the small machine and Elsa's magic had caused the two and their siblings some snow trouble. Their main antagonists presented themselves as a friend to Elsa and Tadashi, which is why Elsa placed Anna's care in Hans' hands while Tadashi tried to save Callaghan. In the Big Hero 6 magna, Tadashi is shown to be good with children and uses his inventions to help them, just as Elsa had used her magic to create ice made items for her kingdom's children.
Similar to how Elsa had lost confidence in herself, a playback in the Big Hero 6 TV series shows that one of Tadashi's filed attempts had nearly got him to give up on himself, but the the thought about Anna and Hiro kept them going. Tadashi's dream is to help people and Elsa was able to do so in Frozen II. Along with the two getting help from others to do so. The two have also spent time in a type of cell for a short time. Just as Elsa isn't afraid to fight those who wish her harm, the Big Hero 6 film and manga have Tadashi being brave in the face of danger.
Tadelsa is considered to be a popular ship in the Frozen/Big Hero 6 crossover fandom. Since Tadashi is a scientist he would probably be fascinated by Elsa's abilities and may want to learn more about them, leading to Elsa having a better understanding and control over them. Fans also see Elsa being drawn to Tadashi's caring nature as he helps her to see that her powers don't make her a monster and how she can be more open around people, as well as the two bonding over them being orphans who had took it upon themselves to watch out for their younger siblings. Since some fans include Anna and Hiro, as well as Olaf and Baymax, in group Tadelsa fanwork. The crossover ship has also been rivalled with Tadanna or have it shipped beside Hiranna.
There are times where the ship is set in Arendelle, but are mostly set in San Fransokyo, where Elsa is commonly seen as a SFIT student that Tadashi takes a shine to. A few manips also have Elsa in Go Go's clothing or a BH6 armour suit. Along with some fanwork featuring both of them wearing Japanese style clothing. The AU's typically have Tadashi part of BH6, while Elsa is typically a civilian girl. The AU of Tadashi gaining power over fire has also featured in the ship, since Elsa has ice magic and it isn't uncommon to ship couples of fire and ice together. In a few versions of a Frozen AU, with the BH6 characters, Tadashi is sometimes seen as Elsa, while in Big Hero 6 AU with Frozen characters Elsa is sometimes seen as Tadashi Hamada. Since there were a few Frozen Easter Eggs and references in Big Hero 6, it got a few fans like to start believing that their films could somehow be linked.
On AO3, the ship only has 14 fanfics while fanfiction.net has 42 with only 17 placed under pairing. Its fanbase on Deviantart and Tumblr, however, it a bit more larger than it is on the two fanfic websites.
- Tadelsa posts on Tumblr
- Elsashi posts on Tumblr
- Elsa makes a appearance in Kingdom Hearts III, while Tadashi was only mentioned in it.
- A few Frozen Easter eggs have been seen in the Big Hero 6 film.
- In "The Present", a reference to the Frozen song, "Do You Want to Build a Snowman?", was made when Honey Lemon asks the villain if they want to build a snowman.
|SHIPS||het||Alariel • DonDaisy • Elzone • Flyelsa • Gothans • Hadeficent • Hiret • Jariel • JiMel • Melgli • Muladdin • Ralida • Shasmine • Tadelsa • Willet|
|femslash||Arianna • Arielsa • Aurelsa • Belsa • Brave Warrior • Casselsa • Cinderanna • Cinderbelle • CindyJas • Desert Mermaid • Elsida • Elswinkle • Frozen Warrior • Honeyunzel • Jasmulan • Jasunzel • Mermaid Beauty • Mermaid Snow • Merunzel • Moanna • Moarida • Moariel • Moelsa • Sleeping Warrior • Tianderella • Violenny • Warrior Beauty|
|slash||Flyaddin • Higuel • Hirbur • PanJosé • Variro|
|non-binary||Elski • Olafmax|
|CHARACTERS||female||Anna • Ariel • Elsa • Fa Mulan • Merida DunBroch • Rapunzel|
|male||Flynn Rider • Hans • Kristoff Bjorgman|