AI-generated song and music video released by yajuman (YAJU-MC) on August 10, 2026 (Beast Day / 野獣の日). Based on the long-running Japanese internet meme culture surrounding Yaju Senpai (野獣先輩 / Tadokoro Koji) and "A Midsummer Night's Lewd Dream" (真夏の夜の淫夢).

It gained significant popularity not only in Japan but also in China, South Korea, and other regions. The original YouTube upload peaked at #2 on the Oricon weekly YouTube chart.

The original YouTube video was removed around October 22, 2026 for violating YouTube’s sexual content policy. This is a third-party reupload.