(#ブラックサンダーの日) What is the story behind this trend in Social Media today?
06-09-2026
September 6 is Black Thunder Day because the numbers 9 and 6 can be read as “kuro,” the Japanese word for black. The date matches both the product’s name and its dark appearance. The manufacturer established the commemorative day in 2021.Black Thunder is a crunchy chocolate bar launched in 1994. It combines cocoa cookies and plain biscuits coated in chocolate and is known for its substantial, satisfying texture. After a slow start it became a national favorite, helped by public mentions from athletes and its distinctive “lightning-level deliciousness” slogan.Every year on this date the company runs light-hearted promotional campaigns that invite people to eat the bar, share photos or comments, and enter giveaways. These activities regularly push the hashtag to the top of social-media trends and serve as a playful kickoff to the autumn chocolate season. The 2026 observances continue that tradition of humorous, participation-based events while also highlighting the brand’s long connection to its main production city.