This is "IROIRO_K" by Chiroru Kamioka, published at C106. It is an unused item, having been kept in a collection. Details (quoted from Melonbooks): This is a book combining Nekomata Okayu and original characters! It includes some of the illustrations and rough drafts of goods! #Hololive #hololive #HoloX Search terms: Tokino Sora Sakura Miko Hoshimachi Suisei Roboco-san Yozora Mel Aki Rosenthal Akai Haato Shirakami Fubuki Minato Aqua Murasaki Shion Nakiri Ayame Yuzuki Choco Oozora Subaru Ookami Mio Nekomata Okayu Inugami Korone Usada Pekora Shiranui Flare Shirogane Noel Houshou Marine Amane Kanata Tsunomaki Watame Tokoyami Towa Himemori Luna Yukihana Lamy Momosuzu Nene Shishiro Botan Omaru Polka La+ Darknesss Takane Lui Hakui Koyori Kazama Iroha Sakamata Chloe Hiodoshi Ao Otonose Kanade Ichijou Ririka Juufuutei Raden Todoroki Hajime Group name... Hololive Vtuber name... Nekomata Okayu