Japanese charcoal toothpaste.
As you might guess, the paste is black.
This toothpaste has a unique flavor - unlike Bamboo Charcoal from China. This one is a bit more antiseptic. It certainly left my mouth feeling clean. And atomic black bowling balls (invisible to the naked eye) are what cause this toothpaste to be so effective... see illustration from the box.
Seriously, apparently, charcoal toothpastes are all the rage in Japan, at the moment, according to my friend Katrissa. (She very kindly brought me the paste from Japan, where she was visiting relatives... thanks, Katrissa!)
I do enjoy the flavor. It's very hard to categorize. If I were versant with wine terminology, I could perhaps describe it better. But since I'm not, here's a lay perspective: fresh, not sweet, slightly medicinal and definitely not artificial tasting.
The website is completely in Japanese, just like the toothpaste package. (The only words in English on the package are the website address, "Made in Japan" and the word toothpaste.)
Google did an interesting job of translating Japanese on the Kobayashi website, rendering phrases such as, "Please be aware of suspicious emails wearing our company."
I was able to find a Chinese English website from Hong Kong that describes the toothpaste... "There are numerous pores on the charcoal particles which effectively attach and remove plaque to whiten and brighten your teeth." (Aaah, much better.)
So if you are able to find a charcoal toothpaste in your town, give it a go!