Going by the volume cover and the table of content, it seems we'll meet the supposed heroine this volume. Well considering this is the last volume (going by the 'Last Act' in the table of content), that should be the case.
Vol. 6 dropped just three days ago(https://www.amazon.co.jp/gp/product/B07QR8TYR9). Not sure if it ended at vol. 6 since all six main characters already have made it in the cover. It could also end in the next volume with all the characters present in the cover or it could end after cycling...
I'm loving these 'going-at-our-own-pace' three even more. Heck, even he knows.
@thebenefactor Thanks again for this work though there were some mistakes.
Those three in the background was the most entertaining part of this chapter. I was more focused on them than the three supposed main characters. Was smirking with the tsukkomi, the teary-eyed "impactful" comment and just going at their own pace. Also had hearty laugh when the doughnut was...