I kind of wondered. I looked ahead through the raws that have been scanned so far a couple of days ago, and noticed there was a blurb at the end of the last chapter saying something about March 2016 (which would be about the right time for Vol. 18 to come out). And things are coming together; the main Ashikabis and Sekireis are gathered, Musubi and Karasuba are having their showdown, and Kouten is close enough to gun down helicopters...plus, Sakura-san said she was ready to wind up the story in an interview a while ago, which is understandable after 11 years. I'll be sad to see it end.
I really hope that Minato will not only entering college,but also will marry his sekireis including Musubi. And then, his harem are allowed to make love to Minato during the bonus chapter. Then they will live happily ever after. With the mature ratings, its a possibly that Musubi and the others will make love to their Ashikabi in Minato.