Well, it is my Distorted comment, but Marriagetoxin is romcom-harem-like, because our protagonist acting like one typical harem-protagonist, but in story that began in 2010 decade, like Yuragi-sou no Yuuna, because this story have action, our protagonist is strong for fight, and the premise, indirectly, is make a harem for his, Kinosaki is more Mea from To Love Ru, but occupies the rule 63 trope, because it is similarly with Gero.

I think that is fine, don't have mistakes, just final point and multiples ways for continues, if author want it. Furthermore, Kaiju n°8 never requested to be hit sales for jump, like the big 3, so this final is understandable from story.