Brand new 2025 doujinshi by Rei Idumi (Izumiya) created as a ¥500 bonus leading up to the digital version of the 10th Anniversary UDDN book from 2012. Originally available for pre-purchase January 26th 2025 and made available online during COMITIA 152 on June 1st 2025 from Melon Books at
https://www.melonbooks.co.jp/detail/detail.php?product_id=2990605
