@Pibata you forgot another thing about Ruka: she gives zero shits about Kazuya being in love with Chizuru, she only pushes herself and gives zero shits about if her actions are contemptible or not. Just think about what could happen if Kazuya decides to cut things with her for good....she could expose Chizuru's job and/or spill the beans about her illness in a cringey melodramatic way out of scorned impulses.
As for the chapter... i think Kazuya will say it. Last panels give a hint he's steeling his resolve. However, there's a thing that is starting to bother me, now that Reiji kind of confirmed story was only halfway in a talk show which topic was encouraging dating in young people and also said in another previous interview the series' finale will be the one people expect the most, but that there gonna be lots of obstacles, problems and deviations until reaching the end (in a way, he said the doesn't matter, because the important thing is the rocky journey to the endgoal).
I remembered a chat from several chapters ago in which Nagomi (kazuya's grandma for starters) told Chizuru her chances of winning Kazuya, even though they're high, are highly uncertain, as well as she told Ruka to be patient because her time hasn't come yet.
There's also the "Future Kazuya as a narrator" thing.
What i mean with that is that, even though story is heading towards a status quo break, and Chizuya become more honest with themselves, how do you stretch a story for another 150 chapters?? Yeah, adding more drama and unwanted situations. This chapter also showed Chizuru is considerate to the point she puts people's position in the current issue above hers (yeah, even Ruka's). So what could be the next plot stretching point?? Yup.
Ruka's disease.
Either Kazuya or Chizuru or both find out her malfunctioning heart issues and could happen these 3 scenarios
1) Kazuya finds out by accident and his head gets filled with worse insecurities and a guilt complex, making his interactions with Chizuru more tense to the point they break contact and Kazuya makes the mistake of going official with the ribbon bitch. Making both Chizuya feel miserable bc one is in a relationship out of guilt and pity and the other starts to feel lonely and also miserable bc Kazuya ain't around anymore.
2) Chizuru finds out Ruka's condition, her selflessness come into play and she decides to cut things with Kazuya, prompting him to go steady with the Sarashina. She instantly regrets it and time makes its deed.
3) a mix of both.
So, whatever the outcome of these chapters ends up being played, there's high chances this could become Domestic Girlfriend 2.0 (on the sense MC starts to date the FMC most direct love rival for real for the sole sake to justify the 2nd half of the series). Even that Nagomi scene reminded me a bit about the fortune teller telling Hina her dream will become true, but not as how she was expecting it (and thatshit happened. She got her happy end, but at a high cost). I'm sticking to the series 'till the very end anyways.