because the plot is very powerful and compelling and the characters are not stuck in the same level. as the series continuous, they tend to grow and mature.. the two series does not focus only in battle but it also gives attention to camaraderie, friendship and a little bit of romance.. and because shonens are mostly for kids attention, they are given lessons to learn as young ones. like how to be strong and brave, to protect and cherish friendship, to keep family values and give importance to it.. and to move on albeit tragedies come thy way.. kawaii.. hehehe