After the gang is swallowed up by Whamon, Sora is holding on to Tai's waist, then lets go when they stop in Whamon's stomach.
When Sora was kidnapped by Datamon, she yells for Tai, not anyone else. (Original version)
Near the end of the episode, Tai was crying after their escape from the pyramid due to his inability (or so he says) to save Sora. This shows that he may have developed some feelings for her.
Sora tries holds him back when he wants to do something stupid.
Tai and Sora have the same interest in soccer and they play together in a team.
Sora is playing tennis instead of soccer now. She and Tai did not see each other so much anymore as they did when they were kids.
Before the events of this movie as Tai had sent her a hair clip as her birthday present. Sora interpreted this to mean that Tai did not like her hat and this lead to an argument with neither sides willing to apologize to each other. Tai resorted to sending an email with his apologies, but had accidentally ended it with "Love, Tai". Kari 'helped' him to send it, making him panic. The email however, was stopped in mid-transmission.
At times around the movie, Sora was about to approach Tai, but always backed out at the last minute. Once she was even at Tai's door but walked away.
In the end, Sora received the email, and she smiled at it, following up by saying, "Stupid Tai."
During a scene in which Imperialdramon Fighter Mode is fighting Armageddemon, and Sora returns, she mentions Tai's name before Matt's upon calling out their names. Also, in a following scene where the two arms of Omnimon (WarGreymon and MetalGarurumon) light up and give their energy to Imperialdramon Fighter Mode, a gust of wind unbalances her and she falls to Tai rather than Matt.
First of all, the Crests. Love and Friendship are quite similar, on the same personality basis. Love could be a certain form of friendship, and friendship could be a certain form of love.
Another thing is that Sora and Matt do not officially show their traits until later in the series. Matt is the "lone wolf", trying to stay distant, not caring about anything besides T.K.. Cherrymon manages to trick him into thinking Tai is his enemy. His friends are not as important to him, until he realizes otherwise. Sora has a problem with love - remember the conflict with her and her mother. She loves her mother, but must remain distant from her because of her different view on life. Also note how DemiDevimon tricked her into thinking she had no love and her Crest would never glow. Their two situations are very similar.
Sora and Matt seem to have lots of similar things together. They are both often alone. They have their own emotional battles when the only people that can help them are their Digimon.
In the scene where Sora got trapped in the darkness, the same one Matt got into, she couldn't come out. Joe tried to get her out, but couldn't. Matt manages to bring her out and even getting Sora to faintly mutter his name.
Tai meets Sora outside Matt's concert, where she has been waiting to give him a homemade treat. While she is shy about going forward with it, Tai encourages her and pushes her to do it.
In the dub of this episode, the dialogue is changed to imply that Tai is initially asking for her to go to the concert with him, and is somewhat hurt when she rejects him.
In the final chapter of the Tokyopop novelization of Digimon Adventure 02, Davis explains that Matt & Sora were married, and had children.
Matt and Sora are shown standing beside each other here (in the back).
When everyone wonders where Sora is, Matt chimes in that she's returning from tennis camp. The reason why no one else knows is because she chose to confide this in him only.
In this CD drama (only in Japanese, Matt actually says to Sora, "Sora, I love you!" while tap dancing to distract Boltmon and allow their plan to work.
In episode two T.K. says he wouldn't mind sharing food with Mimi and comments to Matt," Isn't she cute?" and Matt kind of blushes, saying something like," Forget it".
On the first issue of the Digimon comics produced by Dark Horse Comics, Mimi is drawn with her hand on Matt's shoulder.
Evidence from Digimon Adventure (manga)
In the manga of Digmon Adventure Mimi and Izzy are trapped in some ancient ruins and Mimi runs off crying about how Izzy loves his computer more than her.
Also in the manga, while asleep Izzy dreams about Mimi replying, "Sure Mimi, I'll hold your hand."
Another example in episode 10- A clue from the digi-past, Izzy and Palmon have just found Mimi and Tentomon. Centarumon was going to attack them, and Izzy protected Mimi.
Izzy and Mimi are shown beside each other in this extract from the Finale Poster. This is possible evidence as the other known couples (Matt and Sora who were together in Digimon Adventure 02 and Ken and Yolei who are married) are also showing their coupling (Matt has his arm around Sora and Ken and Yolei are linking arms) in the poster.
Episode 01: Enter Flamedramon
Evidence from Digimon Adventure
When Sora leaves T.K. and Kari, T.K., by the evidence thus far in the series, would be likely to join in with the "bigger kids". However, he instead chooses to stay behind with Kari, even though he could've left her with Gatomon.
Some people speculate that T.K.'s attraction to Kari is simply a result of the promise he made to Sora to protect her, a promise he then carried on to protect her all his life. Further to this, T.K. flat-out agrees to it. The fact that Sora knowingly makes T.K. promise to protect Kari, when naturally the Digidestined would protect each other regardless, suggests that Sora knew there was something, or at least the potential for something, between T.K. and Kari, hence she intended to help them. Also T.K. does not want Kari to see him scared because he wishes to look brave. In the same episode, Piedmon suggests they are "falling for each other". One can take this literally, as the line was uttered when T.K. and Kari are both in freefall, or figuratively - the latter of which suggests that Piedmon observes (or merely jests about) T.K. and Kari's special relationship.
When T.K. first meets Kari, notice that he starts constantly standing next to her. Even before he met her, when he was aware that there would be an eighth child, he remarked how enjoyable the new kid would be if he or she were his age, so that they could play together. It appears his wish is fulfilled, as Kari is only a few months older than he is.
In the second ending, T.K. is shown looking back at Kari. The interesting thing is that he is the only one doing so, as the others are facing the front (with slight exception of Sora).
They are shown standing together in the both Opening Themes of Digimon Adventure 02.
When T.K. walks into Odaiba Elementary and sees Kari again for the first time in a while, they immediately strike up conversation. Most people, upon meeting a friend they haven't seen in years, will exhibit a shy response (citation needed). The lack of this suggests that they feel quite comfortable around each other. The original Japanese dialogue even said, "It's been a long time," and "You've gotten taller." Hikari notably complimented him on this.
When the kids find out that there is a Digimon Emperor, Kari afterwards turns to T.K. and asks him if he's going to defeat the Digimon Emperor.
After the team accidentally left Kari behind, Davis immediately yells at T.K. However, instead of providing the same "crush" response as Davis exhibited, T.K. admits that it is his fault and resolves to save her.
When Kari is under attack in the Dark Ocean, she calls for desperate measures; she calls for Tai, Gatomon, the National Guard, and TK. Notice TK was the only one able to see that something strange was happening to Kari. He also told her he cared too much about her when she confessed her fear about the Dark Ocean. (In the original version, T.K. yells at Kari for being too dependent on Tai; he wants her to be able to rely on people outside of her brother for help.)
The original shows the same thing, with the exception of the National Guard. In the original, she says: "Onii-chan! (This means "brother" in Japanese") Tailmon! (Gatomon's Japanese name) Takeru-kun!
After Ken's self realization and the end of the Digimon Emperor's control over the Digimon World, while they are cleaning up Primary Village, Veemon notices that he can't digivolve. Kari and T.K. decide to run off and try themselves. However, Gatomon is perfectly aware that she cannot digivolve, due to the lack of Kari's crest power, and immediately quotes "No go for Gato," meaning "Don't even bother." There must have been a second pretense to this, as if there wasn't T.K. would have gone himself regardless.
Azulongmon informs the group that the crests of Hope and Light are compatible, suggesting a connection between T.K. and Kari.
T.K. and Kari are the only ones who smile when they say "Digi-Armor Energize!" ("Digimental Up!")
When they go in transport between the Digital and Real Worlds, they always go in opposite directions, while Davis goes in the front. It can also be argued, however, that this is for pure aesthetic reasons; as there is an odd number of people, having the final person go forward would make things even, and Davis's position as leader would only be emphasized by him going forward.
Their Digimon have Angel forms, and their Armor forms are very similar in looks, and even have a default shared attack, something not many have.
As for their Japanese names, they are both spelled Hikari and Takeru phonetically in English, and both are spelled consonant-vowel-k-vowel-r-vowel.
"Yagami Hikari" translates as "Light of the Eight Gods" in Japanese, and "Takaishi Takeru" translates as "Tall Rock Mountain". Mountains represent strength in most Asian religons. Both of their names represent high and celestial things.
This movie formed the third part of Digimon the Movie, and was significantly edited when dubbed into English.
T.K. and Kari travel to New York "partly to visit Mimi, and partly to make Davis jealous". In the original, there is a similar scene (cut from the dub) where Mimi looks at the pictures Hikari(Kari) and Takeru(TK) and states, "Yes, Daisuke-kun will definitely be jealous when he sees these pictures."
TK and Kari are holding hands as shown on the extract of the Finale Poster on the right. This is possible evidence as the other known couples (Matt and Sora who were together in Digimon Adventure 02 and Ken and Yolei who are married) are also showing their coupling (Matt has his arm around Sora and Ken and Yolei are linking arms) in the poster. Their Digimon are also seen next to each other.
It is speculated, based on the epilogue to Digimon Adventure 02, that TK and Kari are married 25 years after the end of the series.
They are shown standing together in the Opening theme of Digimon Adventure 02.