Thanks for all the advice and sharing all your experiences on this issue.  Very helpful!  Just got a response from 2nd and Samurai. Basically, 2nd will not do anything about it. On the other hand, Samurai responded saying that this was normal due to the thick denim. They told me the solution was not to replace the button but to strengthen it. If I send them the jeans, they could firm up the button. I would have to pay the shipping, which I'm fine with. I'm just glad they responded with a solution and I'm going to send the jeans to them.

I had a similar experience when I bought a Redmoon wallet a few years ago.  I had the wallet for 4 months and the concho fell off.  I contacted Redmoon and they told me they could fix it but I had to pay for the shipping and repair.  It sucked, but what could I do?  I went ahead and got it fixed.  It ended up costing around $80.

At least this time around, Samurai isn't charging for the repair. 
Thanks guys!

@Black:

@714hamilton281 firstly, welcome to the forum second, I wouldn't expect that from a new pair of jeans but I've experienced the same on a pair of naked and famous 21onz, I purchased a set of jeans buttons from EBay and used a hammer and a hard surface… Job done

Thanks for the response, however; I'm kinda OCD and would like to get a replacement button from Samurai.  I did email them and also 2nd Japan.  Hopefully they will respond but I don't think 2nd's staff speaks English.

1st post and long time lurker.
I recently bought some Samurai Jeans s710xx 24oz from 2nd Japan.  I received them last week.  I then soaked them and let them dry.  When I tried them on and got them fully buttoned, I noticed the top button got very loose.  Is this normal?  Is it due to the thick denim or is this a defective button?  It bothers me because these are brand new jeans.  Does anyone know if its possible to get a replacement button and get it put on the jeans?  I have several pairs of Samurai Jeans, as well as, Iron Hearts.  I've never had this problem before.  Should I worry or just try to let it go?  I've attached some picks, thanks!