I find it amazing that an extremely small number of fanfic writers seem to notice the severe and troubling issue of Ranma's multiple so-called fiancees. I say "so-called" because not one of the individuals involved can claim him in any way, shape, or form once one takes a logical and/or legal look at the surrounding circumstances. Let me qualify the "legal" aspect with my decided lack of knowledge of any legal system outside of the United States, and not even that one is easily understood by the vast majority of its populace, myself included. With all of the different levels of law (local, city, state, federal) it's difficult enough to know what the "big ones" are, and which ones the average citizen is likely to be nailed with on a whim... which is not to say there are a lot of people being arrested without valid reason, but some of the laws themselves can be a bit too vague and all-encompassing to begin with. With that said, I will continue.
The three big "fiancées" I will deal with are Ukyo, Shampoo (Xian Pu?), and Akane. There are more, I know, but I don't remember their names at the moment (it's been a while since I've reacquainted myself with the anime/manga), and I plan on adding more to this when I'm thinking about it, when I find the time to go through the source material... which may not be anytime in the foreseeable future.
Ukyo has no claim, or at least no evidence of a claim, to Ranma due to the fact that she had already gambled away her family's yatti (the one thing she tends to hold over Ranma's head). On top of this, she has no claim due to the fact that any arrangements Genma made for Ranma were made for a child he had kidnapped after selling to another family (for a bowl of rice, a fish, and two pickles... or possibly something else earlier on), and this occurred with his full knowledge of the Saotome/Tendo agreement, and without the knowledge of Nodoka, who carries the Saotome family sword. There is also nothing in writing that proves the agreement was ever made. Ranma was too young to have had any say in the matter, and Genma had sold the cart, left it somewhere, or destroyed it.
Shampoo has no claim outside the borders of her village, where she had given Ranma a 'Kiss of Death' in which he swore to hunt him down and kill him, regardless of the circumstances. The fact that he has a Jusenkyo curse and that he was in his cursed form at the time becomes meaningless, as he didn't know the local language and was accompanied by a guide (who should have made his customers aware of any of the more esoteric laws or regulations that might have effected them) was enough of an indication that should have allowed some form of negotiation to rectify any issues generated by a misunderstanding. Once out of the village (at the guide's urging), Ranma was then subject to only China's federal laws, and the Village's laws came secondary, especially due to Ranma's citizenry status. Once they (Ranma and Genma) returned to Japan, they were no longer under the influence of the Village's laws in any way, unless one or both of them were extradited to China in order to stand trial for their actions. The fact that the 'punishment' was shifted to 'marriage', the fact that they were in Japan at the time negated any ruling that was made on the matter, as the original 'ruling' was negated as soon as the 'punishment' was changed, and the 'accused' were outside the Village's jurisdiction at the time. The fact that Ranma was in Japan when a Chinese national was trying to force Village laws on Ranma without extradition, would only serve to bring further and much-unwanted attention to the Village (which considers itself to be 'hidden', and 'feared') by claiming Village law holds precidence over any other legal system or government. Considering all of the little tricks, attempts at coersion, druggings, and miscellaneous other plots and schemes to get Ranma into the Village, Ranma might be well within his rights to claim the Village is a danger to Japan and other countries based on what they had done to him, while on Japanese soil, to enforce their laws without regards to Japanese law. As far as the Amazons are concerned, Ranma is currently outside their influence, and any further attempts to 'capture' him may end very badly for the Amazons as a whole. Add in the battles with both Herb and Saffron, and the fact that he won both of them (even if they were both through a lot of skill and even more luck, rather than outright power), the Amazons would have to treat Ranma with far more respect than they seem willing in order to prevent him from striking out at them, or inviting both Herb and Saffron ovet to the Village for a bit of a rematch. In any event, unless Ranma goes willingly, the Village will be in constant danger either from Ranma himself, or the individuals Ranma attracts.
Akane and the Tendo's really have no claim as Ranma had been a kidnap victim for years, and Genma had no legal say as to what happened to him (see "bowl of rice, a fish, and two pickles"). Any claim made on Ranma as a Saotome was invalid as of that point in time, and the fact that Soun makes demands of Ranma and not Genma, even though he is guest in his house, shows that he cares nothing for Ranma, or guests in general, and therefore has no right to demand anything beyond a tanto. The mere fact that Ranma voiced his desire to return to china to find a cure for his curse, and was prevented from doing so, shows that Ranma himself holds no importance to any of those involved in the decision making, and therefore becomes a kidnap victim yet again. Ranma is abused both physically, emotionally, and mentally throughout his entire stay within the Tendo household. He is forced to apologize for things that he has no involvement in. His personal honor is questioned constantly, while his family's honor is apparently nonexistent thanks to Genma (assuming Genma is still Ranma's legal father), and yet both Soun and Genma continue to force Ranma to deal with any and every issue or problem that arises. Nobody questions the fact that Ranma is forced to defend the Tendo dojo in challenges, even though he is not part of the school being challenged. Akane is supposed to be the heir of the Tendo school, though she seems to spend very little time actually bettering herself, nor is it apparent that she is expected to act as such.
Along these lines, Akane constantly claims "I'm a martial artist too!" when Ranma tries to protect her from herself, and yet expects Ranma (or 'someone else') to come to her rescue whenever she realizes she's in over her head. Any time she manages to rescue herself from the situations she manages to get herself into, she does so by accident, and usually finds a way to make her situation worse than before. She never apologizes when she is in the wrong, yet demands Ranma apologize for her mistakes, all while questioning his motives for anything he does.
Akane was chosen for Ranma, though Ranma was the one offered the choice of which Tendo daughter he wished to marry, which he neither made, nor declined. Nobody ever brought up the issue that he hadn't made the decision, and that he still had a decision to make.
As far as the Saotome/Tendo agreement goes, there is nothing in writing that could help settle the issue, nor is there any reason Ranma would be required to abide by the agreement when his treatment enters into the equation.
Update: 10/31/2006:
With my fairly recent understanding of how Japanese law and its social customs work (which is entirely gained through second, third, and even fourth-hand means), only a small amount of the above would actually need to come into play. Apparently, the only agreements that would be put in writing would be agreements between companies or other large-ish entities, or personal agreements where one party has reason to mistrust the intentions of another. So, assume written agreements weren't necessary... at that point, I feel fairly safe to assume that if a person is known to be dishonest, in word or in deed, that those who deal with them regularly would know that they cannot be trusted beyond certain limits.
Keeping that in mind, I happened across a forum topic at fukufics.com discussing the very subject of my rant... well, mostly focusing on Ukyo alone, but it still covers the other two (
http://www.fukufics.com/viewtopic.php?t=100) and I felt a comment by an individual stated the answer quite succinctly. The first message by MageOhki as found at
http://www.fukufics.com/viewtopic.php?t=100&postdays=0&postorder=asc&start=33 actually dealt with all of the "big three" by stating:
"Basically, I'll take the "three" primary "fiancees" in order
Shan Pu: She's a chinese. You're kidding, right? She's got NO claim in Japanese eyes. To be cold, she HAS no claim.
Ukyo: I get the impression that the agreement was between FATHERS. not clan heads, nor families, nor schools.
She's got some possible giri in Ranma's eyes (with or without the dowry) but... that's wiped becasue SHE REFUSED THE ENGAGEMENT.
It's dead, chums. When she stated (Viz, NPR, orginal sorce all have the same vaule meaning) that she was NOT there for the engagement and attacked Genma FIRST (as was right), she negated the engagment.
No engagement there, boyos.
Which, leaves the Tendos.
EOS.
(ANY Tendo. Ranma has NOT by WORDS chosen a fiancee.) "
Which I could still use to remove Akane from the running, since she has removed herself from the running multiple times by both her words and her actions. That Nabiki and Kasumi might still be viable candidates because... well... lets just say that I feel they might deserve a chance, seeing as they were never really supposed to be more than background characters to begin with (even though the same can be said for Shampoo and Ukyo) and were never really developed as characters so much as they were caricatures.