Yes there are things you can sow now but depending on your weather they may need some protection. You will probably need to buy some agricultural fleece (べたがけ), should be wider than your rows to allow room for growing plants underneath. You may also need tunnel struts and plastic sheeting to cover them but this will depend on how much snow you have in your area as too much can collapse the tunnels and break the ridge poles.
Nip down to your local home centre and check the backs of seed packets to be sure but you should be able to seed lots of salad crops now, lettuce, arugula, mizuna as well as komatsuna, spinach, broad beans, some carrots (including baby carrots), some cabbages and I'm sure there are others I'm missing.
Also bear in mind that we will soon be entering the Persephone months when daylight drops below 10 hours a day and plant growth slows down dramatically so plants will take longer to mature until day length rises above 10 hours in early January.
For details on how to construct low tunnels have a read of this thread Season Extension