Mini specials bundled with each Blu-ray/DVD volume of Seireitsukai no Blade Dance. Each special is tied to the new 32-page short story that original light novel author Shimizu Yuu wrote for the limited first pressing of every Blu-ray/DVD volume.

The glittering spotlights. The sparkling, fluffy, cute outfits. The charming voices while dancing with bright smiles. Under the dazzling lights on the big city stage, these would be the mermaid idols who swim and dance freely underwater. But far from this big city, the girls once lived in the peaceful village of Parrel. These girls, who would not even imagine such a glittering future for themselves, are instead just raising a fuss over the snack cakes they are eating. This is the story of the cheerful daily life of mermaids who strive their hardest everyday.

Hakuo Gakuin is on the verge of closing down due to students transferring to rival school Seishikan after mysterious injuries happening to students who refuse to transfer. To protect the school and its students they hire Kojiro, a member of the Fuma clan of ninjas. After finding out that Seishikan has enlisted the help of the Yasha ninja clan, who had been rivals with the Fuma for generations, Kojiro gains the help of his fellow Fuma ninjas. Even though they are hired to protect the schools, the two rival clans vow to destroy each other once and for all so that only one clan remains.