Re: Japanese, Aikido word- for leading?
To me, 吸い込む (sukikomu) is a kind of active movement where tori sucks uke in. I see it as related to centripetal force, like the beginning of irimi-nage (the most obvious). The end of irimi-nage (if you do a big throw) is an example of centrifugal force at work. So, you suck them in and spit them off. But tori is doing it.
'Leading' suggests to me more control of uke's movement. Of course, you could lead (allow their movement to continue in its given direction, with perhaps a subtle alteration by tori) and then suck in. But to me, the sucking in part is active on the part of tori.
Anyway, we all have different interpretations of the same thing and I think it is important to define concepts, words, and meanings so that we can all talk about the same thing and understand each other. Without such, it is impossible to teach/pass on ideas. I'm not sure any of those Japanese words above suitably refer to leading, at least in the sense I understand it.
呼吸 (kokyuu) is an Aikido word and they tell us it means breath/breathing. I think it best to stick to that rather than invent other meanings to suggest what it might mean. Again though, to me, it is the kind of breathing we do in martial arts, where the breathing is coordinated to movement first of ourselves, and second, at the higher level, coordinated to that of our partner's rhythm / movement / breathing. It happens in other sports, of course, but if you name it you can talk about it.