Living overseas and sending money to the UK

kez2

As of December 2017 I moved from the UK to Japan.

Prior to that I was working self employed for 7 years filing self assessment tax returns

I intend to send a sum of around £400–2000 each month to my UK bank accounts.

As my 'domicile' is now Japan (if i'm not mistaken, this is because I will spend less than 31 days in the UK each year) what taxes am I obliged to pay?

mrschaucer

It is unlikely your domicile will change but you will probably become non-UK resident for tax purposes. Have you read this as an introduction? Read the links.
https://www.gov.uk/tax-right-retire-abroad-return-to-uk
You will need to check out your 17-18 split year treatment for UK tax, and then familiarise yourself with any double tax treaties between the UK and Japan.