Seemingly a prequel to Efforts in Business (pool #1893).
Original title: しんらいのあかし
I've tried my best to think of a back story especially for the illustration.
I love ko-Marisas for the most!
(This pool was once used for holding duplicates of 「Forbidden」life (pool #1942), and as the duplicates were merged into the old pool, this pool is now used for a different series.)