How to decide trade name of company in Japan ?
In the case you make a company in Japan, there are some regulations relating to name of your company.
You can include Hiragana (あいうえおetc.）, Katakana (アイウエオetc.), Kanji (愛、宇、江 etc.), Alphabetical letters (A, a, B, b etc.), Number (1, 2, 3 etc.)
So, company named “123株式会社” is OK.
And only a part of symbol is OK.
So, you can not use 「:」「、」「。」.
「東京＆日本株式会社」 is OK.
You can use a symbol letters between letters.
So, 「東京＆日本株式会社」 is OK.
「東京＆－日本株式会社」「＆東京日本株式会社」 is not OK.
On the other hand, 「東京＆日本－株式会社」「東京＆日本株式会社」 is OK.
Change of trade name of your company
Assumed that trade name (=company name) is Amazo Godo kaisha (You used Alphabetical letters).
Then if you hope to change company name to あまぞGodo kaisha (You use Hiragana letters), you need to file registration of change of trade name.
In that case amount of registration tax is 30,000 yen and fee for lawyer will be about 30,000 yen.