Sayuri’s mini-route is the closest you will ever get to something like that. I already made a tip on how to find it in this post here. It’s very easy to follow. 
Somehow I feel like the 90’s was full of that kind of stuff. Where did it all go? 
To be completely serious, though, the opening scene is memorable in every sense of the word. For a person just starting to read Kanon, they will know nothing about the setting beyond ‘it’s snowing’ and ‘there’s a sleepy-sounding girl with an impossible facial structure’. You can dismiss the art style and still be pulled in by the believable reunion of two acquaintances, who then proceed to give you a small taste of their personalities. You, as the reader, can feel this moment is the start of something new and amazing. 
I’m starting to notice this as well through my current reading of Kanon. You can definitely tell that Nayuki and Yuuichi have a lot of history with one another and are far more than emotionally-distant cousins. The awkward familial connection they have makes them feel more like brother and sister than just another girl to woo, adding to the realism of the setting. Yuuichi admits that the idea of living with a cousin of the opposite sex is cause for gossip, but Nayuki’s charisma and level of trust with her peers goes to show that no one really cares. Even if they did gossip, it wouldn’t last long enough to matter because it’s readily apparent they act more like siblings.
The chemistry between Yuuichi and Ayu, on the other hand, is a byproduct of the idea of Yuuichi befriending a complete stranger with behavior that seems less than normal to him. In fact, each side’s perceived view of ‘normal’ is contested as they converse, and it’s hilarious to read (or watch, if you’re prefer the anime). This doesn’t change much over the course of the story, but it is still interesting to see how close they become through their hijinks.
In fact, you could say that for pretty much every other ‘stranger’ Yuuichi meets, with varying degrees of snark attached to it from Yuuichi’s front.
