Sometimes I buy a product based only on its name, and this was one of those times. The name isn't quite as funky as it sounds though. This is a candy bar affiliated with the "Black Thunder" line of products made by Yuraku. I believe the "thunder" parts relates to the fact that the bars are full of crunchy cookie bits.
I thought this might be an attempt to market a special line of candy bars toward women, like the ill-advised "Fling" candy bar. Further investigation seems to reveal that it is based on an anime show. Products based on anime are a dime a dozen in Japan, so that was a big disappointment. The bar could have contained some secret estrogen-enhancement ingredient, or been formulated for female tastes (not that I'd know what that is), but, no. It's just a boring name based on a cartoon.
Fortunately, the bar itself is actually pretty good. Like the other bars in this line, it is small, about 3 inches long by 1.5 inches wide (7.6 cm x 3.8 cm) and made with very weak and soft chocolate. The shining star of it is all of the little cookie pieces that pepper the interior. They're not too dense so they're not incredibly hard, but they are pleasantly crunchy. The bar has a nice cookie flavor coupled with coconut and cocoa.
There's no nutrition information on the bar, but considering the original Black Thunder was about 100 calories and this is very similar in size and composition, I think it's safe to conclude this is about the same. I found this in Family mart convenience store for about 25 yen (31 cents) and would definitely buy it again. If you like Twix or chocolate-covered Oreos, there's a chance you'll like this. It's not as sweet as those, but it has the same pleasant cookie qualities.
