This is a question that's been nagging me, and I felt I should ask. Before anyone brings it up, I knowthat Ranma and co don't stand a chance of being to learn most, if not all, of the techniques from Dragonball or DBZ and I know that even if Ranma could learn the Kamehameha, or its equivalent, it would probably never be as powerful as the one Master Roshi fired off the first time it was displayed in the series. However, what I'd like to hear people's opinions on is if the basic principles of the Kamehameha could be used as a workable technique in the world of Ranma 1/2.
Now, I've seen the scene in the Dragonball anime where Master Roshi first displays it, and I've read the manga of that same scene, but it's been some time so please bear with me if I'm mistaken. The fundamental principal of the Kamehameha is that the user concentrates and draws all of the ki from their body and concentrates it into a sphere of spiritual power in their hands, focusing it tightly and then unleashing it as a beam of destructive force. Correct? Well, something similar, at least in the anime, is stated to be how the Moko Takabisha and Shishi Hokodan work: in their case, the user focuses on a particular emotion to generate ki that is focused into their hands and then unleashed as a bolt of force, while the Perfected Shishi Hokodan instead launches that generated ki into a pulsating cloud of energy overhead, which is then allowed to drop like the proverbial ten ton weight. Seeing these similiarities, is it really impossible that something like the Kamehameha could exist in Ranma's world?
Now, don't get me wrong, when first learned, this is definately going to be a move with flaws. At its initial training, the move is very much a oneshot gambit: because the user is drawing up all of their ki for a single attack, whether it hits or misses, they're going to collapse from exhaustion immediately afterwards: they've used up their stamina in this one attack. Further training, of course, will enable a master to launch lower-powered Kamehamehas, which will lack the sheer punch, but will also not drain the user so badly and can be fired more quickly.
Yes, I know that the characters in Dragonball don't get exhausted from using the Kamehameha, except for Master Roshi after using his first one of the series, but let's not forget that those who use it in series are aliens who are insanely powerful, to the point they can devastate planets just by gathering their battle aura.