I'm optimistic, since it's obvious she likes him and the author's trying to show it in every chapter now (cf. the first page of this chapter with the heartbeat sound effects, the end of the last chapter, and the start of the chapter before that), but there's still too much that's unresolved. There are people complaining about how long this is taking in every chapter's comments, but it can't just stop here and that's just the nature of long romance manga. To end it now would be very strange, too, since this is still ranked third among serialized titles in Weekly Shonen Magazine despite premiering in 2017. The anime adaptation is also getting a second season, so it's not like this is an obscure title they're going to be looking to cut off.
I think Sumi's storyline could be wrapped up now, since it's a nice full-circle sort of thing where she helped him (the date idea) after he helped her (when she was first starting the job). I don't know what to expect with Ruka—that could be close to the end, but I could also see it drawn out for weeks—and we haven't seen Mami since the few frames of her meeting with Kazuya's grandma. In all likelihood, that'll be another protracted story spanning a few weeks.
I don't think the author can get away with setting this up for them to not realize their feelings for each other at this point—especially when all the panels of inner thoughts and flashbacks from both characters' perspectives are converging on the memory of that one date and their feelings for each other—but it's not like they're going to start dating and all the other characters will just throw a party. We'll be here for a while yet, I think.