Before and After Ken
I think that the relationship between Davis and Kari changed after Ken's arrival in the digidestined group. I will show you some examples and you can agree with me or not.
Before:
We all know about Davis's feelings for Kari at the beginning of the second season. We could say that he was a little obsessed with Kari, he always wanted to do whatever she did and the most important thing - he was really jealous of T.K.. T.K. was Kari's good friend from the past and Davis thought T.K. wanted to take Kari from him. In dubs he showed his disliking even by calling T.K. by other names (like T.A. or T.P.). Kari never showed that she would like all the attention but she also didn't seem to hate it. She just ignored it. Often she ignored Davis too if he said something, she just turned herself to T.K. and asked him about his opinion. Davis saw that but he still tried to gain her heart. He even had some crazy ideas on how to make Kari to fall in love with him. He thought that if V-mon digivolved to some kind of Angemon, Kari would feel more connected to him and would start to like him. He wanted to beat T.K. in everything, even in basketball (T.K.'s sport). However, he didn't seem to have any success. But then Ken came and everything changed.
After:
Davis wasn't jealous anymore, he wanted Ken to be a part of his DigiDestined group and that's how Ken became his best friend. Their Digimon even had a DNA digivolution together. When Ken was kidnapped, they were trying to save him. They were following the truck that took Ken and when Kari left them to fight with Ladydevimon, he didn't say a word. Normally he would want to go with her and would be afraid for her. Davis stayed with Ken most of the time and finally Kari started to show another attitude to Davis. When Ken was trying to defeat the darkness and Davis was helping him by saying he is not the same person anymore, Kari said to herself that she can feel something warm and asked herself if this could be Davis's heart. When Ken and Davis came back from a fight, she was the one noticing it and was really happy about it. In one of the last episodes Kari was following Oikawa's car and when T.K., Cody, and Yolei joined her, she asked where Davis was. In dubs she was asking after Ken too. There was a very interesting moment in episode 46. Davis tried to talk to a dark spore child but he didn't succeed it. He apologized to Kari and Ken for failing. Kari's reaction was really suspicious. She said that he did a great job and that it wasn't his fault. Gatomon had to calm her down by saying that they all knew that and that she didn't have to react like that.
There is also one interesting comparison. There is a CD cover for Digimon music where T.K. and Kari are standing in the back and Davis gives them a jealous suspicious look. And there is also a poster probably made later with all DigiDestined on it, T.K. and Kari holding hands and Davis and Yolei holding Ken's hands. Davis doesn't seem to be bothered by T.K. and Kari.
But Davis's love didn't just die, just his attitude changed. In the fourth movie, when Kari and T.K. were fighting against Diablomon, Davis and Ken saw them on a big screen and Davis wanted to go after her to save her.
Even though Davis's attitude to Kari changed, he didn't seem to lost interest in her (at least that's what we can see in the last movie, episodes may say something else). Kari's attitude to Davis changed a lot too when he stopped being so pushy with his love towards her.
