The Tanto is Not a Tanto (And Why That’s Okay)
David Sun
Shodan Essay
June 2026
Tomiki Aikido is unusual compared to other martial arts with a combative competition rule set in that our primary form of combative competition features asymmetrical combatants. Under this competitive format an unarmed Aikidoka is pitted against another who is armed with a foam training tanto. On the surface this seems to simulate a scenario in which the unarmed Aikidoka, hereafter referred to as “Toshu”, must defend against an attacker armed with a knife of some sort. However a deeper examination reveals significant flaws in the rule set of tanto randori if we look at it as simulating a realistic encounter against a knife-armed attacker.
To put it bluntly, the rules of tanto randori do not respect the tanto as an edged lethal weapon. Cuts with the edge are not permitted in randori at all, despite the fact that Japanese blades are famous for their sharpness. The scoring area is limited to the chest area; the head and neck are naturally forbidden for understandable safety concerns but hits to the hand and arms are not counted despite these being no more dangerous to target with the training tanto than the chest.
Most egregiously the player wielding the tanto is penalized for “stabbing too close” if they make a thrust without the full extension of the arm. This rule neuters the knife where it is actually most dangerous. This rule is simply stupid if we consider simulating realistic knife defense to be the goal of tanto randori.
The effect of these rules is to allow Toshu to defend themself with tactics that are effective within the confines of the rules yet reckless in the knife fight that tanto randori superficially simulates. These tactics include extending the arms toward the player with the tanto with an aim toward parrying the expected thrust, but also exposing their arms to be cut. A wounded arm may not be as immediately fatal as a thrust to the abdomen, yet an Aikidoka would still find themself greatly hampered in their ability to grasp or form tegatanta if the tendons in their arm were severed. Toshu is also encouraged by these rules to seek safety by proximity to the knife-wielder – even if the knife hand is free Toshu cannot be scored on with easy stabs so long as they remain close to the player with the knife, despite the fact this this is also the perfect range for the tanto player to turn Toshu into a piece of cloth in a sewing machine.
Tomiki Kenji (1900-1979) was a renowned martial arts instructor who lived and taught during some of the bloodiest and most devastating wars in human history. He was responsible for teaching hand to hand combat to the Japanese Military Police in Manchuria during the Second World War. He also taught members of the Allied Occupation Forces after the war. The men he was responsible for teaching were no strangers to inflicting and receiving brutal and lethal violence. Undoubtedly Tomiki Sensei knew how a knife worked and what a blade could do.
How then can it be that the martial art bearing his name has such silly rules for simulating a knife fight? The only rational answer is that tanto randori is simply not meant to simulate a knife fight. But this answer only leads to further questions: if tanto randori is not meant to simulate a knife fight then what is it meant to do? And what is the benefit of practicing with a training knife if that knife does not act like one?
The answer to the first question is actually quite simple: the purpose of randori is to practice and test Aikido skills against a live opponent who is resisting in earnest. Rules, be the formal or informal, are necessary both for participant safety and to focus the training to a particular skill set. A particular advantage of a formal rule set is that any two participants from anywhere can meet and have a common expectation of what constitutes acceptable behavior. An Aikidoka from Venus and an Aikidoka from Pluto can meet for the first time on the mat with a judge from Madagascar without a common tongue shared between them and yet all three will have the same understanding that they can expect to take falls on the mat with joint locks but should not expect to be choked unconscious. Furthermore the rules must focus the training to a particular skill set: one goes to Kendo to learn attack and defense with a sword thus the rules generally prohibit the use of other weapons than the sword, including the use of
unarmed techniques even where such techniques might be used in real life. The same must be true of Aikido.
What then is the skill set that Aikido randori is meant to promote? Tomiki Sensei tells us in his 1959 book Judo Appendix: Aikido. He states in a chart showing the relationship between Judo and Aikido that the Aiki techniques are a “system of techniques in the applying of which it is considered most ideal not the be seized by the opponent (Tomiki, 1959, p. 91)”. In Aikido: Tradition and the Competitive Edge, Shishida Fumiaki and Nariyama Tetsuro present a similar chart to the one Tomiki presented which states that Aikido techniques are to be used when the combatants are “some distance apart (Shishida & Nariyama, 2001, p. 179). Furthermore, Tomiki Sensei in his essay On Jujutsu and its Modernization claims that Aikido randori is meant to be train for situations where “an opponent, from a distance, tries to strike, lunge at, or kick you, or with a weapon tries to cut or stab you (Tomiki, trans. 1986).” He states Aikido randori is a form of practice “where you would avoid your opponent’s attack from a distance… and then apply a technique would [sic] utilize the atemi-waza and kansetsu-waza (Tomiki, trans 1986). None of these Sensei claim Aikido randori as a method specifically for practicing knife defense. Rather they cite the need to train at avoiding an attack at a distance and Tomiki Sensei suggests the possibility of weapons in general, not just a knife.
Man has a particular genius for devising weapons with which to murder his fellow man. Historically one might face a sword or a spear, in Tomiki Sensei’s formative years the bayonet was still in use, and of course the humble kitchen knife will always grace our homes. Additionally any number of tools and objects could be improvised in a pinch for attack and defense. One of the goals of Tomiki Aikido was to create a system of Aikido randori that could be practiced all over the world; it would be simply unfeasible to create a unique rule set for international competition for every weapon that could be conceived of. Furthermore some weapons are easier to practice with than others. Juken (bayonet) randori could have been practical in the 1930s but perhaps would have brought back too many bad memories of militarism in the 1960s. Why not Shinai randori then? That would certainly enforce the
need to keep distance and allow one to train against an opponent with a significant reach advantage but it also would have required everyone to purchase protective armor which is quite expensive, hampers movement, and is inconvenient to don and doff. Additionally, with Aikidoka being thrown about quite regularly, the danger of injury from landing on a weapon is not inconsiderable. A foam tanto is small, does not require extensive protective gear, relatively cheap, and is unlikely to cause injury if dropped or landed on. The foam training tanto is simply the most convenient and safest choice.
Why not treat the tanto as a tanto then? Different weapons all have unique properties that affect their handling: where a knife might be particularly dangerous up close a sword is significantly safer once you have closed distance. If the goal of tanto randori were to practice specifically techniques against a knife it would be best to treat the tanto as closely to a real blade as safety permits. However as established above, this is not the goal of Aikido randori. Thus it is acceptable to sacrifice “realism” so long as we receive something of value back from the exchange. What then do we get back from allowing Toshu to cheat the knife? If Toshu closes to grab the tanto player’s unarmed arm without care then Toshu might be as good as dead if we assume the tanto to really be a tanto. The thing about being dead is that it is not necessary to train for being dead. Budo is partially about training for death but that is about the spiritual and psychological aspects of dying rather than the physically being gutted part. However in a scenario where the armed assailant has a sword or something else there is still a lot of opportunity for Toshu to salvage the situation. If we simply allowed the tanto player to use the “prison sewing machine” technique we would lose the opportunity to practice techniques that are feasible on weapons other than knives.
Furthermore by treating the tanto as a tanto in a realistic fashion we would rob the tanto player of the opportunity to practice Aikido. Under the current rule set the tanto player cannot simply rush Toshu and must choose their opportunity to thrust carefully, setting Toshu into a state of broken balance before fully committing to a thrust. It might be easier and more realistic to just bull rush Toshu and lay
on with the old sewing machine thrust, but the limitations placed on the tanto force the tanto player to develop what Kendo calls seme: pressuring the opponent into giving an opening.
In conclusion, the tanto is not a tanto. It is a training tool, chosen for convenience and safety, to allow Aikidoka to practice the general skills of their art against a live and resisting opponent. Although tanto randori takes its name from the tanto it features, tanto randori is only superficially resembles a knife fight and is not intended to simulate one. It is a training game for developing and testing skills in general rather than a simulation of a specific scenario. Thus certain aspects of realism have been sacrificed on the altar of pedagogy and intentionally so. With these facts in mind we can better understand the benefits and drawbacks of tanto randori: because the training is general rather than specific we can more easily transfer our skills to other scenarios. Taisabaki that works against a knife will work against a jo, a sword, or a crowbar. However because the training is not specific it also does not totally prepare us for the unique properties of any weapon, if we practice blindly. If practical real life application is a goal of our Aikido, then it isn’t enough to say “it works in randori so it works in real life under any circumstance”. We must give critical thought to how a technique would play out under different situations. Although I have been critical of certain tactics I have observed in tanto randori, these criticisms are only valid in the context of an unarmed unarmored fight against a knife wielder. Even the act of extending ones arms toward a blade becomes extremely sensible if one has a shield of some sort, easily improvised if one has a jacket or bag at hand. Because randori is a general practice rather than a specific simulation the skills it develops are relevant to the unarmed civilian, the armored riot cop, and the soldier in 1930 or 2026; whereas a simulation of a specific situation would be less generally useful. Therefore, the tanto is not a tanto. The tanto is anything we do not want to be hit with: the tanto is a bayonet in 1935 Manchuria, the tanto is a spear in 1185 Japan, the tanto is a baton in 1992 Los Angeles, the tanto is a sword, a crowbar, a baseball bat, a booger on a finger, the tanto is a bike careening down a path about to collide with us. The tanto is anything we need taisabaki to get out of the way of. And of course, sometimes the tanto is a tanto.
Works Cited
Shishida, F. & Nariyama T., (2001). Aikido: Tradition and the Competitive Edge. Shodokan Publishing, USA
Tomiki, K. (1959). Judo Appendix: Aikido. Japan Travel Bureau
Tomiki K. (1986). On Jujutsu and its Modernization. (R. W. Dziubla, trans. & F. Shishida, trans.). Tomiki.org
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