Konrad best boy methinks.
and omg guys please chill. first of all it's a fiction. second, they're both children and they are good friends! even though he will most likely become the love interest later, the most important thing right now is that he is her friend! a friend that she can talk to! a friend that gives her advice! and i'm so happy that she has someone as respectful and kind as Konrad as her friend!
the author is taking her time in developing Leslie's character, and human relationship is part of that. you all should focus on that instead of arguing over age gaps. Why are you all acting like they're already dating? Remember right now Konrad and Leslie are friends!