Japan bank preferred mortgage loans

Hi all. I was able to get a loan for a mortgage with Shinsei Bank but it’s lower than we anticipated. I was wondering if anyone had any experiences securing a loan with another bank that maybe less conservative on the loan amount? In short, I’m debating if I should try to secure a loan with another bank institution to see if I can get a larger loan or if the banks all use a similar methodology to calculate the loan amount.
Background: US citizen with Japanese spouse. Live and worked in Japan for a few years with stable income.

by CGekko