craftgrrl | A kimono and a question

Now, my question is....

In the second photo, I have the 'obi' pinned to the mannequin and in the third photo, I just tucked the
fabric in to get that look.

What can I do to attach the obi instead of using pins?
I suppose I could use safety pins. I'd be afraid of damaging the fabric though.

I could tie it in a knot and make a bow but this obi is wide and it bunches (well, it does on the mannequin,
not so much on me) when tied.

I should have planned to have it wrap around the body and left the patterned part right at the end of the obi
but alas, I wasn't thinking clearly! :P

Any ideas?
I want this to be 'adjustable' so most people can wear it so buttons or ties at the back wont really work.

Thanks! =^-^=