Fake Aikido

Renowned Aikido master Ryuji Shirakawa has been releasing a series on YouTube titled "Fake Aikido," in which he encounters practitioners of other martial arts and combat sports to see whether Aikido techniques hold up against these athletes. His goal is to demonstrate that Aikido techniques are not "fake" — as many claim — but are, in fact, effective.
In a recently published episode, he met with sumo wrestlers from the Oshima stable. This stable is run by former sumo wrestler Asahitenho Oyakata (元力士の旭天鵬親方).
The original YouTube video is 15 minutes long; the clips shown here feature a few selected techniques.

Demonstration

Following the polite mutual greeting, Shirakawa Sensei demonstrates a series of Aikido techniques. As always, his movements are highly dynamic. His uke must be very athletic; it is clear that this style of Aikido is intended for young, athletic individuals who enjoy being whirled through the air in this manner.
Clearly, this style of Aikido does not align with what is taught in Ki Aikido. However, the explanations provided in the following videos may also prompt you to question the given rationales and develop your own thoughts on the matter.

Nikyo - kote mawashi

To demonstrate the techniques, three younger sumo wrestlers (力士, rikishi) step into the sumo ring. They do not attack; instead, they allow the techniques to be applied to them. The sole objective is to test their effectiveness.
The first technique is kote mawashi (小手回), a move referred to as nikyo in most styles today.
Shirakawa Sensei explains how he positions his hand, noting that the joint lock he applies causes such intense pain for his opponent (相手 aite) that the latter is compelled to go to the ground to escape the agony. He adds that this remains effective even when the opponent is of a large physical stature.

Kote gaeshi

Next, Shirakawa Sensei demonstrates the technique kote gaeshi (小手返し). He induces pain in the wrist, pain that only subsides once the opponent chooses to fall down.
The sumo wrestler is completely taken aback by the effect and insists that he is not just acting.
Shirakawa Sensei explains that he bends the opponent’s wrist while simultaneously rotating his own body around a central axis to amplify the effect which is what causes still more pain.

Shihonage

Shihonage (四方投げ) would be a specific technique used to immobilize an opponent's shoulder joint as well as his elbow.
A more dangerous variation occurs when the opponent's body is also twisted.

Tenbin nage

A gentler technique is tenbin nage (天秤投げ), the "balance-beam" or "scales" throw. This technique makes use of the opponent's joint structure. The sumo wrestler, however, remarks that the technique is not gentle at all.
Shirakawa Sensei explains that, ideally, the opponent's elbow should also be blocked; however, the throw can still be executed effectively by sliding one's arm under the opponent's armpit and using the movement of one's own body.
The sumo wrestler still finds it too harsh, noting that he nearly broke his arm. Shirakawa Sensei replies that if one knows how to fall properly, it is really not that bad.

Sankyo

Now he employs the sankyo (三教) as an articulated lever, using it to maintain control over the opponent or to pin him to the ground with a "sickle grip." It is a technique for making an arrest.

Hakucho no mizumi

The final technique is hakuchu no mizumi (白鳥の湖 — "Swan Lake"), which is employed when there is a significant weight difference between the individuals involved. It utilizes the shoulder blades. When asked about the throw, the sumo wrestler explains: "Before I knew it, I had already been thrown (私は気づいたら投げられてた。)."
In this technique, one dives beneath the opponent and executes a throw without relying on any joint locks.
Ultimately, the sumo wrestlers remark that while Aikido may appear staged, it is, in fact, genuinely effective. The false impression arises because the techniques are performed with such extraordinary skill.