I kinda noticed this whole "Riders parents died before the beginning of the series" plotline thing a couple of days ago too and I gotta say, the writers are really overusing this thing. Seriously, can't they try something original? Its getting pretty old hearing the same old rehashed, "My parents died a long time and ever since that day, I vowed to bring all evildoers to justice" story. Are the writers trying to make all their Riders a japanese version of Batman or something?