Natto is often sold in packs of 3 or 4. It is difficult to eat it all by the "best by" date, so I use this method to keep it fresh. A lot of people don't know this method, so I thought I'd share it here.

Chopped natto won't come unstuck quickly after freezing, so microwave for a short time to loosen. It is easier to mince if it is still mostly frozen.
I tried a pack that was stored for 4 months, but the texture wasn't good and the grains were dehydrated. I recommend keeping the natto for up to a month. Recipe by Nanaha778