St. Michael Girls’ School has published an online short story leading to the events of A Kiss For The Petals Revolution! As in the visual novel Rinagisa, the prologue concerns Rikka and Sayuki volunteering to serve as guidance counselors to the students of the St. Michael’s annex school. The translation by Ralen is hosted on this server as a mirror of the original product page for Revolution.
The index page for Revolution contains a copy of the cover image for Rinagisa that may not be safe for work.
The translation is hosted here at http://petalsgarden.axypb.net/trans/rev/index.html