The partnered forms practice of aiki-ken is called kumitachi (組太刀:くみたち?), meaning the crossing/meeting of swords. There are five kumitachi in Saito's aiki-ken curriculum. The kumitachi teach students how to alternately control the center line and move off it to avoid attacks and how to blend with an opponent's attacks, among other skills.
- Ichi-no-tachi (一の太刀): first of sword
- Ni-no-tachi (二の太刀): second of sword
- San-no-tachi (三の太刀): third of sword
- Yon-no-tachi (四の太刀): fourth of sword
- Go-no-tachi (五の太刀): fifth of sword
- Kimusubi-no-tachi (気結びの太刀): blending one's energy with partner of sword
Improvisational variations on the kumitachi (called henka), which generally cause the kumitachi form to end early with one person taking advantage of an opening to strike or throw the other, are also taught.