Help identifying natto type

Hi guys,

I generally love natto, except a few weeks ago I had this really bad natto at my sister’s house. My sister (who also loves natto) also agreed that it tasted really bad, and she doesn’t know why.

[This is a picture of the packaging of the bad natto](https://imgur.com/UG8SMtv).

As I recall, the mustard tasted too strong and the natto was too tart and harsh.

I can read Chinese (hence Kanji) and some basic kana as well as speak some very basic Japanese, but am otherwise Japanese illiterate. I can’t really identify any words on this packaging that I can associate with the bad taste.

This is as opposed to other Okame Natto company products I’ve had, [like this one I bought on sale and am loving on a near-daily basis at the moment](https://imgur.com/9z4WaXJ).

What is it particularly that is making the red-packaging natto taste bad? Is it the type of natto? Or a different sauce combination?

Would really appreciate if someone could teach me how to identify that particular type of natto so I don’t buy it in the future. I’m mostly Japanese illiterate so my current strategy is to just grab the cheapest natto on sale and go.

Thanks!