As far as I know, Ai Men is simultaneous Men attack from both players and Debana Men is when one reacts intuitively and attack Men before the other starts his or her Men strike.
I have read some comments in Facebook which claims that Ai Men actually is not a technique, it is just a way to describe that both players strike at the (almost) same time, because one of them must have strike first.
I saw these two interesting instructional videos about Ai Men in youtube and I want to share them to you. Using my very basic Japanese , I only can figure it out some general ideas, so maybe you may want to help me out with translations:
Video 1: in this video, it explains that the timing and the distance (maai) is important for Ai men, and the difference between "ippo no uchi 一歩 no 打ち and Tai o okuru uchi .
According to the video, the ippo no uchi seems more effective that Tai o okuru uchi.
Video 2: This video explains this Ai Men technique which the both players`shinais should not touch (Aite no shinai ni sesshoku shinai uchi, I think it pronounces in this way) , and what I am able to understand, one of the player strikes the Men off-center, so their shinais will never touch or hit each other, while the body moves slightly towards the right, like the basic Do strike.
Also there is "Kiri Kaeshi Men", in which one of the player moves to strike Men from Ura side of the shinai, interesting.
In Nuki Men from Omote, the player who perform the technique moves a little bit his head towards right so his actually misses the Men strike. Is that correct?
I appreciate a lot if you can give me more details about these videos.
Answer: Thank you for your question and sharing the videos with us. I thought I introduced those videos to the patrons at patreon.com but I probably shared something different.
I knew these videos. And it is quite interesting.
Video 1: Ippo no uchi is done without stepping in while the other person is doing so. So you are not moving at all because your opponent is coming forward. If you know the moment when your opponent comes in, you can do that. A lot of sensei executes this type of men strikes on us :)
Video 2: Two ways to strike men in order to avoid your shinai from touching your opponent’s shinai; one is to step to your right and strike from the side and the other one is to step to your right and lean your body to your right.
But it is harder to accomplish this men from the era (the left side). Then he came up with this technique he calls or maybe there is such technique called, “kirikaeshi-men”. I have never heard such techniques so I am not sure the name is well known or not.
So you need to have your opponent to think that you are going to take a step to your right. Then as you and your opponent are striking men, you turn your shinai around from the right side to the left side to strike the right men of your opponent.
And he talks about men nuke men. If you step straight backwards like Kata No.1, due to the modern kendo’s nature, your opponent’s kensaki will be stuck on your body. So you need to step to your right or left. But if you do that obviously, your opponent will follow you. So…
Intentionally slide the kensaki of your shinai off the center to the left (your opponent’s right) by stepping to your right slightly when you are still in chudan, That will cause “<“ with your shinai and your opponent’s. At this moment, your opponent will feel weird a bit. Then when your opponent comes for your men, you strike his/her men.
The men strikes before kirikaeshi-men in the video 2 are not really Ai Men. They are more like Men Nuki Men. The definitions of techniques are pretty hard in the modern kendo now because kendo and kenjutsu have become so different now.
I hope you understand my explanations but if you don’t please let me know.