Black Thunder (Japanese: ブラックサンダー, Hepburn: Burakku Sandā) is a chocolate bar made and sold in Japan by the Yuraku Confectionery Company (有楽製菓株式会社, Yūraku Seika kabushiki gaisha).

In 2008, the Yuraku Confectionery company sponsored the Men's Gymnastics team at the 2008 Summer Olympics, and brand recognition correspondingly increased.

Starting in 2008, Yuraku Confectionery company began developing and marketing variations on the Black Thunder bar.

In 2009, Yuraku began collaborative efforts with other agencies to develop related products inspired by the Black Thunder candy bar.

The original concept was a candy bar that would have three main components, a heavy texture, rich flavor, and a reasonable price; the combination of these qualities would ensure that it would be an easily marketable product.

The Black Thunder bar was then developed based on the original concept specifications but also with the idea that it would appeal to multiple demographic segments, including children.

In 1994, a small factory with only 20 employees in the city of Toyohashi in Aichi Prefecture began making the Black Thunder chocolate bars.

[1] The packaging at that time used alphabetic script that read "Black Thunder", and the suggested retail price was set at 30 yen.

In August 2003, the package was changed again to its current design, in which alphabetic font for the brand name was replaced with Japanese lettering in katakana.

Finally, a new advertising slogan aimed at a specific demographic was added to the front of the package: "A big hit among young women!

[5] Though initially distributed only to 7-Eleven stores in the Kantō region, a potential for expanded marketing was realized, and Black Thunder was released for sale through a cooperative business association into more areas.

By the end of the year, over 900,000 units had been sold and Black Thunder bars were the best-selling product of the Yuraku Confectionery Company.

In 2006, it was picked up by the Shiraishi-san Co-op and sold over the internet, and product sales received a boost as it gained in popularity among university students.

Yuraku has produced a number of variations on the original Black Thunder bar, with different target demographics, or in collaboration with other commercial ventures.

The flavor of the Dear Girl Thunder bar was advertised as "The Taste of First Love: Salt and Chocolate" (初恋の味・塩チョコ Hatsukoi no aji: Shio-choco).

In July 2009, a limited edition of 480 units of the Dear Girl Thunder bar went on sale and quickly sold out.

[17] Within a short time, the White Thunder bar has proven to be quite popular, as demonstrated by the rapid depletion of stocks.

Intended as a breakfast bar, the Morning Thunder contains a cinnamon-flavored cookie mixed with peanuts and soy bean puffs, fortified with extra protein, and coated in milk chocolate.

The slogan on the front of the package states: "Protein and peanuts in a filling chocolate bar" (ブチプロテイン＆ピーナッツin満足系チョコバー Buchi Purotein ando Pīnattsu in Manzoku-kei Choko Bā).

[20] Black Thunder Next Gear (ブラックサンダーネクストギア, Burakku Sandā Nekusuto Gia) is a long-form chocolate bar with almonds.

The McFlurry Black Thunder would be added to the McDonald's menu in Japan, and would be available for a limited time, starting 16 August 2017.