How to calculate capital gains tax when the stock is transferred from another company

Let’s say the timeline is something like this.

* I received 100 stocks in a general account in company A. At that time, the stock was worth 1,000 yen per stock
* Then, I transferred all 100 stocks to a new general account in company B. At the time of transfer, the stock was worth 600 yen per stock.
* Finally, I sold all 100 stocks at 1,200 yen per stock.

How do I calculate capital gains for this situation?

The profit report from company B uses the acquisition price of 600 yen per stock to calculate a profit. My profit would be (100 \* 1,200) – (100 \* 600) = 60,000 yen. But in reality, my acquisition price is 1,000 yen per stock. So my actual profit is (100 \* 1,200) – (100 \* 1,000) = 20,000 yen.

I don’t want to pay the tax more than I need to.

Thanks.

by recobe182