Well actually I've found both spellings and dunno which one was the right one ^^'
However I think you're right since heiki means weapon in japanese,
Which means 60% of french/german sites have made the same mistake
Anyway I have the DVD box for a while and I think that it was worth buying it...
I've seen it, too much "I'd do anything for you" stuff in there, I still think its worth watching and very sad, I for one found i have an inner soft spot hahaha