Sonic illustration anthology, SONIC IMPACT is available for pre-order now.
You can pre-order it online:
[link] (Surprisingly, a half of the number of stock already have been sold.)
That Dojin book will be sold at Comic Market this winter.
ComicMarket WebSite To Attendees from Overseas:
[link]
Our booth address is 東ﾊ- 41a(Eastern Ha-41a), the circle name is　"RoseHip", the owner is "Ezume" .
She will also be another Sonic Dojin books in store. Please check the information at her pixiv account. [link]

The booth next to her is Makoto-Hirono's. He is the comic artist of Sonic on DENGEKI, and prepares Sonic Dojin book of SatBK.
Sample:
[link]

Another booth of Dojin book that I participated, 遠い音楽（TOOI ONGAKU:Music from far away） is 東パ　25a(Eastern Pa-25a), the circle name is "アンニュイ・キャットの庭" (Garden of a cat with ennui), the owner is "posaune".
Sample:
Book cover: [link]
Body of the book: [link]
That book is an novel written in Japanese only. If you can read Japanese, I'm sure you shall love it. The author Frede is the best story teller in Japanese Sonic fandom, I think.
She will sell the book at online sooner or later. I will make an announcement about it when it becomes available.

Please let me know if you have any question. ^v^ Thank you!