I have two problems with this story.  First, since Nodoka admitted that
Yohko and Ranma were not engaged as children, on what grounds can she
dissolve the other engagement?  Second, I see Ranma's reaction as
very OOC.  He respects his mother, and I can't see him using vulgarities
with her.  I do think that he would politely demand to know why family
honor required him to marry Yohko. 

                                                  dml