Mentioned a German edition consisting of the first book and an English translation -which will soon include "Apron"- but only just became aware of a Taiwanese edition because of this "Short-cake" decorated
Twitter message. Turns out
Tong Li has been publishing this series as well. Apparently starting with
牽牛花與加瀬同學 back in 2013.
Side note: As of January 13, advance tickets are on sale for the limited theatrical release of the OVA in June 2018.