This was fucking hilarious & sexy at the same fucking time omg. 2 years late, but blessed to see how this turnt out, one day maybe a sequel of a 4 way of the girls kissing etc
Now that you mention it, on looking at the bottom panel of page 1, there appears to be a similarity in appearance between the male and female partners of each couple. Just maybe author-san implied that Yuuchi saw in Mizuki an older version of the girl he really liked (Kumi), and likewise, Kumi saw in Tsukasa an older version of Yuuchi.
BWAHAHAHAHAHAHAHAHA! ... Well, That Was Something Completely Unexpected; but everyone seemed satisfied with their respective hook-up. Also, "Good Job" exchange between Yuuchi and Tsukasa ... priceless.
Well, there's only one thing that could happen in a secluded storehouse like that.
And hey, of course the two people they liked were already going out with someone...That is to say, each other.
But hey, considering their comments when they saw the two going at it, they seem to care for them in their own way. So one could say that they were wingmen for the young couple?
Great ending though. How did things turn out this way, you ask? Well...Hentai. And really, I'd have it no other way.