plus size formal wear

Hello

I know it is kind of a frequently asked question, but I haven't found an exact answer sorry.

I have to buy (as soon as possible) a plain white shirt or blouse (the kind that most office ladies/school uniform have).

I have never had troubles finding clothes in Japan, except for this.
Having a quite big chest, I hate to shop for shirts, as I always find myself having troubles fastening the 2 buttons that are right ont op of the breast areas.
(I am a E-cup by the way, but it seems that japanese e-cups are a little tight-fitting for me even...)

I am sure that I should be able to find such clothing stores in Tokyo, but my problem is: where?

Thank you

depending on a budget:

first - department stores - like Tobu or Seibu or another one like Isetan etc etc. They all have a special ''Plus size'' section on one of their floors. Tobu has Plus Size clothing, Isetan - Clover plus, naming could be different so it'd be better to ask at the information desk. This is the more expensive choice, but you'll be able to buy something as soon as you find it.

second - www.nissen.co.jp - they have a large selection of big size women clothing (and formal too), but you'll have to wait until they deliver. And you have to be fluent in Japanese or know your way around internet translators :)

I've found some items from Shimamura that were business appropriate. Also, at Uniqlo, you can go to the "Men's" area since they are technically unisex. Some of the cuts might not be so figure-flattering though.

I'm currently interested in some purchases from Nissen. But I was wondering about the quality of the clothing. A lot of the items are awfully cheap, so I'm worried that it might fall apart after a couple uses. Does anyone have any experience ordering from Nissen?

WryRhie - I order from them at least once a month and about 5-6 things at once. For the last 3 years only had to return 3 things (shoes, jacket and tunic). Mostly due to the size not being right.

It's not a "brand" quality, but definitely very good. It helps to read the reviews - 口コミ - they have under almost every item. It usually helps avoiding any problems.