The Diagonal Cut: Movement 8 of the 31 Jo Kata

This article examines movement 8 of the 31 jo kata, focusing on what happens before the situation covered in the companion article "Using a Sword to Study 31 Jo Kata."

Using a sword clarifies this movement because the blade orientation and cutting angles become visible. With a jo, the same principles apply but are less obvious.

Movement 8: The Turn and the Weapon Behind

Movement 8 begins with awareness. You've finished with the opponent in front. You turn your head to check behind. Is someone there? When you see a new threat, you react.

The sequence has three phases:

Look - head turns to see behind
Turn - body turns on the balls of the feet
Cut and step - the weapon descends toward the right while the left foot steps forward as counterbalance

This is a reaction with little time. Though there are three phases, they happen very quickly.

When the body turns on the feet (phase 2), the weapon stays behind. With a sword, this is what you see:

Top of the blade at neck height
Hands at hip level
The weapon at roughly 45 degrees
The tip pointing away from the new opponent

This is the starting position for the cut. The weapon is behind you, ready to descend.

In phase 3, the cut descends diagonally toward the right. This creates lateral momentum that could pull you off balance.

The step with the left leg counterbalances this movement. The foot goes forward not to advance, but to stabilize against the blade's diagonal path. Weight stays on the rear leg. The front foot acts as counterweight to the cutting blade.

In the third phase, when we start the cut, we stay behind the weapon. This is where power comes from.

The Diagonal Cut: A Unique Angle

In Iwama weapons training, we typically perform all cuts vertically and centered. The purpose of suburi is to learn body centering and movement control. A centered cut teaches you to organize your entire structure around a central axis.

Movement 8's cut is different: it travels diagonally, descending from high to low, from left shoulder height toward the right hip. This is a cut not found in the sword syllabus, an off-center cut that requires different control.

Descending Diagonal, Not Lateral

Saito Sensei performs movement 8 as a diagonal. However, depending on the video source, the movement can appear more horizontal and less like a cut. This probably explains why some understand it as a horizontal sweep, left to right at belly level.

However, a quarter-circular movement on the horizontal plane pulls you to the right, causing structural instability.

The sword suggests a different approach. With a sword, you feel that a descending diagonal, high to low, passing by the shoulder, is more natural. The cut works like a standard suburi but angled. This path finishes at hip level, keeping your structure stable. The downward component works with gravity rather than against your balance.

With the jo, the horizontal sweep seems logical. With the sword, the descending cut feels more natural. The sword helps explore why a descending path may offer better stability.

Why Diagonal, Not Straight

The position after the turn is compact. The sword has traveled to the side and we bring it back by passing along the body. The cut happens in a very reduced space.

From here, we could do a straight vertical cut. But the attack is coming toward us. A straight cut meeting a straight attack risks ai-uchi, mutual killing, where both strike at the same time.

The diagonal cut avoids this. By cutting off-center, we move off the line of attack while still delivering our cut.

Additionally, when we turn and step with the left leg, we naturally move slightly off the attack axis. Even if we do nothing more than continue this momentum, we may already be just out of reach of the incoming cut. The diagonal path works with this natural movement.

With a sword, staying on the left with a more restricted movement could allow a thrust. Since we're exploring the kata through the sword, this is a valid variation to consider.

The greatest distance we can reach is at shoulder height. The closest target is therefore higher than the belly: it's the head, or the hands if the attack comes from a weapon. Also, a low movement doesn't protect against a descending cut. This is why I prefer targeting high rather than the belly.

A high attack also allows you to deflect a descending weapon, similar to a pak sao in Wing Chun, redirecting from left to right. The descending diagonal angle accommodates both offensive (cutting) and defensive (deflecting) possibilities.

Critical point: do not transfer weight to the front foot. Loading the front foot would cancel the counterbalancing effect. The rear leg remains your anchor, allowing you to push off it to move forward.

This weight distribution also prepares you for what comes next. If you need to move immediately (as in movement 9), you're already loaded on the leg that will power your next action.

Four Variations

Movement 8 can produce four different outcomes.

Variation 1: stay on the left (sword only). After the turn, instead of letting the sword swing diagonally to the right, you stay on the attack axis. You can transition directly into movement 9 without your weapon having passed to the right of the opponent's. In this case, movement 9 becomes something different, closer to the first cut of the first kumitachi. This preserves the same body feeling as the standard movement.

Alternatively, you could thrust directly. This is probably very dangerous, as you remain in the line of the descending attack. Not recommended, but it's an option worth knowing exists.

This variation only works with a sword, not with the jo.

Variation 2: cut reaches the forearm. Your cut contacts the opponent's forearms. This is a successful interception. You cut through and the encounter ends here.

With a sword, this would be a decisive cut. With a jo, you're striking the forearms with sufficient force to stop the attack.

Variation 3: cut contacts the weapon. Your cut contacts the opponent's weapon rather than their arms. Your diagonal cut deflects their weapon to your right.

This deflection opens the central attack axis. The opponent's weapon, pushed aside, no longer threatens your center. From here, you can:

Rotate your wrists
Cut from right to left toward the head

This is a successful technique through redirection. You didn't cut the initial target, but you created an opening and exploited it.

Variation 4: no contact (the kata's case). Your cut doesn't connect. The opponent withdraws their weapon from your range, or the distance is wrong. Your cut sweeps through empty space.

The opponent, unaffected by your cut, continues their attack. They deliver another descending strike to your head.

This is the variation the kata teaches. This variation allows continuing to the 9th movement of the kata.

The Rebound: From Movement 8 to Movement 9

The cut that didn't connect still has energy. The weapon traveled through its diagonal arc and arrived at your right side with momentum.

Movement 9 is the inverse of this cut, the same diagonal path but ascending instead of descending. The cut goes back up in the other direction. The arrival position of movement 8 becomes the starting position of movement 9.

This creates a natural flow. The energy of the outgoing diagonal cut feeds into the incoming ascending cut. Understanding this connection helps the kata feel less like a sequence of separate techniques and more like a continuous exchange.

The need to control the weapon at the end of movement 8 (bringing it to vertical on your right) reflects the intensity of the original cut. A fast, powerful diagonal movement requires deliberate control as it completes, or the weapon will continue past its intended stopping point.

The companion article "Using a Sword to Study 31 Jo Kata" explores movement 9 in detail: its two phases, the wrist rotation, and how the opponent's next attack can be used to power your counter.

Practical Takeaways

In solo practice, focus on the three phases: look, turn, cut with step. Keep weight on rear leg throughout. Feel the front foot as counterbalance to the descending blade. Practice controlling the weapon's arrival at your right side.

In partner practice, explore all four variations: thrust (sword only), forearm cut, weapon deflection, no contact. Notice how where contact is made changes the outcome completely. Feel the transition from movement 8's completion to movement 9's beginning.

The diagonal cut is unusual in Iwama, since most cuts are centered. The kata shows the no-contact variation, and movement 9 is the response. Movement 8's energy flows into movement 9 through the rebound effect.

Conclusion

Movement 8 can end in four ways:

You stay on the left, leading to something closer to the first kumitachi, or thrust (sword only)
You cut or hit the forearm and finish
You deflect the weapon and create an opening
You don't connect and must continue

The last three share one thing: you cut while remaining on the left of your opponent. The kata shows the fourth variation, because when a movement ends the fight, there's nothing more to teach.

Understanding the diagonal cut, its descending angle rather than lateral sweep, the three phases, the counterbalancing front foot, provides context for why movement 9 exists and how its ascending cut relates to what came before.

Next article: Using a Sword to Study 31 Jo Kata continues from here, exploring movements 9, 10, and 11, the ascending cut that inverts movement 8's diagonal path.

Cross-References

Related Articles:

Using a Sword to Study 31 Jo Kata - Movements 9-10-11
Why Iwama Emphasizes Weapons - Foundational context for weapons training

Related Technical Content:

31 Kumijo Comprehensive - Detailed technical breakdown

About This Article

Metadata	Value
Author	Thomas Mangin
Created	2026-02-03
Last Updated	2026-03-17

This article was developed with assistance from Claude (Anthropic) based on concepts, insights, and detailed verbal explanations provided by the author. The ideas and interpretations come from the author's training and experience; the written expression is Claude's.