It was available on [url=https://web.archive.org/web/20210125155014/https://shop.solpress.co/collections/visual-novels/products/yotsunoha]SolPress shop[/url].
*Note: The product page and its associated community have been rejected by Steam on May 9, 2019, with no provided reason.
Does not include the CGs and voice acting from r1166.