Do you think this volume is the last? Or we're going to have one more to match Lonely Girl (6 vols)?
I feel like there's quite a bit left to cover that I'm not sure how they would be able to fit it in 4 more chapters (if it were to only go to the end of vol5.)
If we assume next chapter is round 2 which Haru stated this chapter was a month away, then we still need would need to do round 3 afterwards, resolve the family stuff, potentially do a debut once they're fully in the company, resolve the Haru / Yuu, and explore Hikari a bit more.
I think it's fairly safe to think it'll go to at least 6, unless Kashikaze REALLY crams in stuff in these chapters or we get some crazy time-skips.