This is the omake that comes in set with that Formidable doujin by sky during C97.
Also, I have an ongoing survey for my trip this C98. I plan on scanning the latest book this C98. If you're curious/interested, you can view the details here:
(Under the "HUGE PROJECT FOR THIS YEAR: C98 TRIP") https://trello.com/b/KZkOaJ8n/obsoletezero-workboard