>>49272368Don't take it so seriously, just one more crackship of this anime.
Now if you want to see it from a realistic side, the childhood friend is an unrealistic cliche, growing up with someone produces an imprint effect similar to the one we have with our family, unconsciously repelling them as a future partner (It also happens with animals) , so as soon as new people are known they are more interesting.
There are exceptions as in everything, but the media likes to romanticize this concept in an exaggerated way, when the reality is the opposite, these relationships are rare and hardly last.