Read the ending and I feel it pretty satisfsctory on its own way.
I mean: sorry dudes and dudettes, but good endings are not about a literality. In the figurative way Kotoyama made it, it's totally unneeded a finale with Hotaru in marrying dress and Coconuts waiting for her in the church and kiss each other.
The two semi-final chapters (184 and 185) pretty give us all the proper context we need to know to get why final chapter 186 is truly cool. Even way too before, Hotaru was very clear with Saya regarding her feelings for Coconuts. Remember: Hotaru went from forcing Coconuts to take over his father's store, to want him (in the possesive way) just for herself, to finally accept his mangaka dream and still loving him in despite of that.
Of course, considering the last page, Hotaru just got there for an answer from Coconuts and he was ready to give it, and I'm pretty sure dude didn't wait for that moment just to tell her "Sorry, marriage is a no-no"
And even if you're not convinced, you still have the "epilogue" chapter from Volume 11, where Hotaru spent the night in Coconuts' room while he and Hajime fulfill the deadlimit for his manga, where the "Calory Queen" told him to get a proper sleep time because she would worry if he got sick, a hint about both having already a romantic relationship.
Seriously, I thought the final was a disaster, considering people here destroying it. But with this final chapter, I have big expectations for "Call of the Night" finale.