This image is one of the covers of a traditional RPG rulebook called "Yuu yake ko yake" (ゆうやけこやけ), published by Sunset games. Ike also made the other covers which regrettably aren't posted on his pixiv account. He did publish a couple of doujins based on this story.

It also seems to have some tie in with the manga "Neko Musume Michikusa Nikki", also done by Ike.

---edit, some more information about the RPG series---

The official title is Honobono attakaro ru pureingu (ほのぼのあったかろーるぷれいんぐ). Sunset games published four settings/rule books:
1. Yuu yake koya ke (ゆうやけこやけ), see image above for the cover.
2. Mono noke koya ke (もののけこやけ)
3. Hitotsuna ko-michi (ひとつなこみち)
4. Korekara no michi (これからのみち), see my other post for the cover.

The setting for the RPG is a modern day city which is filled with "youkai" (demons/spirits etc...) and humans.

--- I do not know Japanese so I can not give proper translations of all the titles.
Also do not know all the names of all the characters shown in the image. The only one known is Tamae (with the fox ears). Although she is been listed as part of Neko musume michikusa nikki she has never been in the official manga (only in the doujin of Ike).
---
Sources I've used:
http://www.sunsetgames.co.jp/rpg/youyake/youyake.htm
http://ja.wikipedia.org/wiki/ゆうやけこやけ

You know, there's a game translation group that's trying to develop an English-language version of this game.
They haven't started their Kickstarter campaign yet, but they should be doing so soon.
Here's the link if anyone else is interested:
http://starlinepublishing.com/our-games/

So, Starline Publishing has started their Kickstarter for the English translation of the game and it has already reached it's full funding goal.
But they still have a full month before they're done and a large number of stretch goals for the project, so please consider contributing to this project if you would like to see it happen:
http://www.kickstarter.com/projects/nekoewen/golden-sky-stories-heartwarming-role-playing