Protože sám jsem v některých věcech trochu perfekcionalista, pátral jsem, jestli něco takového v samuraiské historii kdy bylo - a nešel jsem:
Následující do angličtiny přeložený text psal Rónin Musaši na počátku 17. století (zjevně ambidextr a ještě měl improved two weapons fighting):
Because I hold two swords, I call my fencing style two-sword swordsmanship. Holding a sword in my left hand (as well as my right) implies nothing special. It only helps me gain the skill to be able to hold a sword with a single hand (instead of gripping one sword with two hands as was customary). If a man were galloping along a narrow path near a river or if he were in a battle crowded with samurai, he would hold his shield in his left hand, thus restricting the free use of that hand. He would then have no choice but to grip his sword only with his right hand. (Without training) he will feel that sword inordinately heavy. Only when a man has experience and is accustomed to wielding a sword with one hand (can he excel in battle.) When an archer becomes experienced by shooting arrows in training, his shooting ability soars. When a man becomes accustomed to riding horses, he can command a horse well. This is not only true of martial arts but can also be applied to the everyday. For example, with practice fishermen can excel in rowing and farmers in plowing. In the same way, men, with experience, can attain superior ability with a sword (wielding it in one hand). Needless to say, a swordsman must choose a sword that corresponds to his physical strength.
Velmi zajímavý článek, který mě potěšil

Zdroj: http://www.kampaibudokai.org/Niten.htm
Když ještě něco zajímavého vypátrám, dopíšu to sem
Edit: Na fóru, kde jsem k tomu došel (http://forum.katana.cz/viewtopic.php?p=6790) byl ovšem výše uvedený anglický překlad zpochybněn... Kdo ví, třeba Catigern opravdu vymyslí něco nového
