Kotarou's nickname is "Kotarou the Runner".  He's a master of defensive battles, and minimizing losses when things turn bad.  His quiet, unassuming nature and the way he fights make him less likely to stand out than his other friends.  However, if he was put up against a real foe, someone who he couldn't beat unless he gave up on running, you might just learn his true name...
Even with ships that can travel the stars,
،حتّى بوجود السّفن الّتي تسافر عبر النّجوم
Aunque tenga una nave voladora,
Mesmo que as naves possam
 viajar pelas estrelas,