. . . but wouldn't it technically be "Souma"? 
From the point of view of an English speaker, the 
spelling "Sohma" might make sense, but when you 
get right down to it, I don't believe the 
Japanese *have* a character that sounds out 
as "oh". . .

Personally, I think the "h" was added for the 
benefit of making the name look only slightly 
foreign without confusing the too many Americans 
who get flustered by seeing multiple vowels in a 
row. ~_~

Many Sharp Smiles,
--Drac (who fully believes in stupidity. . . or
        maybe I only encountered too many examples
        of it today at work. . . ~_~)