I believe that when we were young, when we were young and ignorant, we had a crush on the best boy or girl in our class, or we had a crush on the tall and handsome basketball captain in our grade, or we might be attracted by the boy who studied worst in our class but had the most personality. In this cartoon, Akagi Haruko, as Akagi Takenori's sister, naturally appears beside the handsome guys on the basketball team, which is very reasonable. As the most handsome, coolest and talented player in the basketball team, Rukawa Kaede will naturally be concerned and loved by many girls. Akagi Haruko is also an adolescent girl, so she will naturally pay more attention to Rukawa Kaede.
As the protagonist of Slam Dunk, Sakuragi is not a talented player, neither steady nor handsome, but with his love for basketball, he gradually got used to it. In the process of accompanying Sakuragi to grow up, Akagi Haruko was attracted by some high-quality qualities of Sakuragi and began to have different feelings for Sakuragi.
The people we like when we are young may not be 100% people who live with us, because love when we are young is simple and beautiful. When we step into the society, the real pressure and demand often cover up our pure love, so Sakuragi and Rukawa Kaede may or may not be with Akagi Haruko when she comes of age.