Touhou Natsuyasumi(Summer Vacation) (東方夏休み), also known as Kasu(Residue)☆ (カス☆), is a promotional video Cookie☆ voice drama that was directed by “Kazuya Mishou” (美翔カズヤ) and published on August 10, 2014.¹⁾ It's a low-effort album advertisement that the community was quick to burn.

The story begins with Reimu and Marisa fishing. Alice stops to talk about an upcoming concert at Koumakan because Remilia started a band. Marisa swiftly signs the three of them up, despite none of them having any experience with music, and it's revealed that the loser would have to do the winner's bidding. They get a month to learn and practice, this passes, and we're finally taken to the aforementioned concert at Koumakan.

At the concert, Remilia's 'Devil Cats' and Marisa's 'Blare Witch Project' are announced,²⁾ but Marisa ended up running late and the Moriya Clan jeers at her. Eventually, Marisa arrives just in time, rocks out, and wins the crowd vote. In contrast, Marisa refuses to order them around and simply thanks them for giving them a chance to play, then they have an afterparty that Flandre ends up crashing as she was locked up.

Kazuya was inspired to create a voice drama after Taisa's retirement, which did attract some hype as Esuka from Cookie☆☆ S3 was involved, but the final product turned out to be a massive disappointment, plus the community in-jokes were too blatant and corny. The only 'good' thing that people got from it was the very brief Peanuts-like scene. Kazuya retired and the voice actresses vanished as they used fake names.

• The only reason it isn't 'Gomi(Garbage)☆' (ゴミ☆) is because another video has that name.

• Cookie☆☆ S3 - For Esuka's prior appearances.
• Kusso☆ S2, KusoKuri☆ - For Koga's later appearances.

• Touhou Natsuyasumi on Niconico Douga
  • Touhou Natsuyasumi (English Subs) on YouTube
• Kasu☆ on the Cookie☆ Explanation Wiki
• Kasu☆ Transcript on the Cookie☆ Jikkyou Wiki