ずっと一緒に下校してたけど応援の甲斐あって一緒に帰れない日が増えてしまった仲のいい女友達からもらったアメチャンです

It's candy that she received from a good female friend with whom she had always gone home together but, thanks to her cheering on that friend, the number of days they can't go home together has increased.