The Japanese customs states:
Personal effects and unaccompanied baggage for personal use are free of duty and/or tax within the allowance specified below.
There is an exemption for your personal and work effects without ceiling (considering the quantity is not huge, a laptop is definitely covered. To be on the safe side, get a letter from your company that the work laptop is company property)
Personal Effects and Professional Equipment
Clothes, toiletries, and other personal effects for your personal use, as well as portable professional equipment that will be used during your stay in Japan, are all free of duty and/or tax, if they are considered quantitatively appropriate and are not for sale.
For the duty-free ceiling, it is defined as:
The total overseas market value of all articles other than the above items must be under
200,000yen. Any item whose overseas market value is under 10,000yen is free of duty and/or tax and is not included in the calculation of the total overseas market value of all articles. There is no duty-free allowance for articles having a market value of more than 200,000yen each or each set.
The Japanese embassy in the US states:
Most new goods or items intended as gifts, which have a cumulative overseas market value over 200,000 yen, are subject to a 10% duty charge on the combined value of all the items. Such goods will also be subject to the 5% consumption tax, which is based on the goods' value including duty charges (if any).
Which means that they consider a gift towards your personal allowance.
Looking at completed sales on ebay.ca for a used Intel MacBook Pro 2020, the prices hover around CA$800 and CA$900 depending on the config and the condition
From Xe as of April 13th 2023, CA$850 is roughly equal to JPY84,000, well below the JPY200,000 duty-free limit
To ease your entry back into Canada, you may want to look at this page about personal items bought in Canada
If you are planning to travel outside Canada with highly valuable items that you acquired in Canada or that you lawfully imported, you can take them to a Customs and Border Services Agency (CBSA) office before you leave to have them identified on a wallet-sized card as valuables that were in your possession before leaving the country.
Take the card with you when you travel and show your card to the border officer if you are questioned about these items when you return to Canada.