Sugar Song to Bitter Step is the upbeat ending theme for the 2015 anime series Kekkai Sensen (Blood Blockade Battlefront), performed by the band Unison Square Garden. The meme took off due to the infectious choreography of the show's characters dancing in formal attire. It quickly became a redraw phenomenon, where artists across various fandoms—ranging from Haikyuu!! to VTubers—would animate or illustrate their favorite characters performing the same high-energy routine. The meme captures a sense of chaotic joy and the contrast between a 'bitter' world and a 'sweet' attitude, making it the go-to template for celebrating fandoms and catchy musical moments.