Hiro and Yokai/Callaghan. Both are genius inventors who lost a loved one and most of their actions in the film were driven by their grief and need for revenge. However, whereas Hiro learned to see the error in his actions and accept his loss, Callaghan was too mad by their grief to change and refused to let go of their bitterness. Also, Hiro was surrounded by friends and family who supported and helped him get through his depression while Callaghan kept their pain private and didn't tell anyone.
GoGo Tomago to Wasabi's overcautious driving skills; her readiness to pick up the speed in car chases sharply contrasts with his safe driving instincts.
Robert Callaghan and Alistair Krei are explicitly set up as foils at the expo, with Krei wanting to profit off of Hiro's invention and Callaghan trying to persuade Hiro to use his talents for something more. This sets up the reversal when it's revealed that Callaghan is actually Yokai.
Whereas Baymax is quiet and built to help heal people, Mini-Max is bombastic and built to prevent as much property damage that Fred could cause.
Megan Cruz to Karmi and Trina. All of them are female acquaintances to Hiro, are around his age, and have had Ship Tease with him. Karmi is his rival at SFIT and despises him (except for his alter ego) and Trina is what Hiro would've been like if he had stayed in bot-fighting and also turns out to be a villain and Obake's "daughter". As for Megan, she's an ordinary girl who has no problem getting along with him and the two hit it off pretty well and become friends. Unlike Karmi, she is a threat to Hiro's superhero life rather than a source of help to it, but unlike Trina, the threat is of a good-natured variety rather than a villainous one.
Megan Cruz to Hiro Hamada. Megan is a normal 14 year old kid with interests, attends high school and loves to have fun. Hiro never got to live a normal life due to being a Child Prodigy growing up and being a superhero in the present day. He also doesn't do activities outside of school, his internship at Krei Tech and superhero missions, making him wonder if he misses out on being a normal 14 year old kid.
Grace Granville to Robert Callaghan. While Callaghan was generally lax and seemed to be a Reasonable Authority Figure, Granville is more no-nonsense. But while Callaghan ultimately succumbed to his own anger and ended up not caring for any of his students, Granville is only tough on her students because she wants them to be at their best.
Karmi's interest in germs and pathogens — which can hurt people — contrasts with Hiro, Tadashi, and Baymax's focus on healthcare and rescuing people.
Diane "Di"/Liv Amara to Alistair Krei.
Unlike Krei, Amara is passionate about her scientific work, worked hard to get to where she is, and is generous and willing to help people, even if she may be a bit oblivious and does seem to have an ulterior motive. Krei, on the other hand, is a businessman and not scientist and leaves the work to his disgruntled employees, and can be a Corrupt Corporate Executive that doesn't care about what happens to people unless it gets really bad, either because he has a sense of decency or doesn't want to get in legal trouble.
Additionally, Liv Amara tends to be dismissive (as shown by her Kick the Dog moment below) towards those who don't share their area of expertise while Krei tries to be approachable to anyone of any talent.
There's also the way they treat their interns. At first, Krei sees Hiro as a Mouthy Kidhe doesn't want to deal with, but their relationship evolve into a mutual respect, with Krei acting almost like a father to Hiro. As for Liv, she acts like Karmi's best friend, but it's all an act. She couldn't care less about her, manipulates her, uses Karmi's inventions for her own goals, is ready to kill her if she gets too close of her plans and finally mutates her and forces her to attack Hiro.
Diane "Di"/Liv Amara to Karmi.
Both are two-faced in different ways. Karmi's "nice girl" act was only in front of Granville to annoy Hiro, and dropped it by "Failure Mode". As for Liv, she gives herself a nice mask in public only to hide how monstrous she truly is. Also, Character Development turns Karmi into a Jerk with a Heart of Gold, while Liv becomes more immoral and villainous as episodes go on.
Both are passionate about their scientific work and would rather not interact with people if they aren't interested in that same passion. While both biologists, Karmi has a strong sense of morality by how she was ready to work in a basement with Orso Knox on the loose to ensure that he gets cured, and also by how she cares about Hiro's well-being despite not getting along with him. As for Liv, she has no sense of morals, doesn't care about the consequences of her actions, and is even thrilled to commit them.
They also seem to be a bit oblivious about how their male counterpart feels about them, with Amara being unaware of Krei's envy of her and Karmi being unaware that Hiro, a boy she sees as her rival, is the hero she crushes on. Both Krei and Hiro also express immaturity when talking about their female counterparts as well.
Chris appears to be one to Globby. Just like Globby, Chris is a henchman of the Big Bad, who's simultaneously competent andFun Personified. But while Globby committed a Heel–Face Turn and helped the team defeat Obake in the Season 1 finale, Season 2 has Chris being loyal to Liv to the end. It's justified since he is Liv's creation, after all.
Similarly to Di, the real Liv Amara also one to Karmi. Both are the loner type and biotechnology prodigies. However, Liv is what Karmi would've become if she didn't learn to trust people; while Karmi started as a loner and eventually opened up to people and made friends, Liv only relied on herself (literally) and ended up creating an unstable clone who broke the law repeatedly and put innocent people in danger, who in the end only ruined her reputation.
