The way they dance around each other really is depressing, especially with my expectation of how this story is meant to end. I'm pretty sure it's not meant to be between them. But they keep fooling themselves into thinking maybe, just maybe... It sure does seem like a great match, doesn't it? But they're just so pessimistic and shy about each other that they can't really progress that last step.
By the time they would work their shit out, Raku will probably realize he actually loves Chitoge as much or even more than he does Kosaki. That's the way I'm seeing it, at this point. These chapters between these two just tease a relationship that might have been doomed the moment Chitoge collided her knee with Raku's face, which was the first interaction between Raku and a girl, after the initial flashback premise establishment, that was depicted in this story.
If Chitoge didn't come here, maybe Raku and Kosaki would have gotten together eventually. But Chitoge is here, now. There's a reason for her being here, with Raku the way they are now. Raku just needs to search his own heart and realize it is already conflicted. What if that conflict is why he keeps flubbing confessions with Kosaki? His heart knows he's not actually serious and forces him to reel back at the last moment. But it's the only love he's known for years, now, before Chitoge, and he started out so fiercely against associating with the fiery blonde he can't see what's right there.