Like kenjutsu, bojutsu is one of the 18 disciplines of ninjutsu, and mastery is required to perfect ninja training. Staff (kon) techniques have been a part of martial arts in eastern Asia for thousands of years, carried down over the generations into modern schools like kobudo and koryu budo. Bojutsu teaches that the weapon is an extension of the body, and therefore its basic movements include thrusting, slashing, and striking.
Closely related to bojutsu are naginatajutsu (naginata technique) and sojutsu (spear technique). Both weapons
Sojutsu is the discipline of spear (yari) techniques. Weapons of sojutsu are distinguished from naginatajutsu by the shape and size of the blade at the end (often shorter and straighter than the curved naginata). The spear holds a special place in Japanese mythology; the creation story says that the Japanese islands were formed from salt water dripping off the end of such a weapon. Spears were easy to produce in the feudal era, and thus gained popularity in battle. Their versatility made them usable both while on foot and horseback.
It could be expected (and, indeed, probably accurate) that because the staff, spear, and naginata share similar shapes and sizes, that a master of one would have little trouble being a master of all three. If that is the case, then Donatello is arguably further along and more advanced in ninjutsu training than any of his brothers, including Leonardo (having mastered at least three of the 18 disciplines to Leonardo’s perceived one). In his most recent incarnation, this is actually implied to an extent. Donatello’s bo now transforms into a naginata when pressure is applied to a particular spot. Donnie has been shown wielding the naginata with the same ease as he does a normal staff, and a spear would not be terribly different from either.
The choice of weapon also adds to other aspects of Donatello’s character. In all versions, Donnie has a special bond with April O’Neil, taken so far as to be a true crush in the most recent incarnation. This bond runs deep, and may even tie in to April’s ninja training. If the naginata is the weapon of choice for female samurai (and possibly female ninja), then Donatello being the staff/naginata user will allow him to connect with April further should she choose such a weapon.
Mastery of bojutsu offers its users adept skill in several disciplines of ninjutsu. Anyone willing to make the effort to perfect it is well on his or her way to being a true ninja. Donatello’s personality and commitment to those abilities that extend the reach of man- and mutant-kind give him a distinct advantage for bojutsu work, and put him closer than any of his brothers to becoming a ninjutsu master.