If the Mystery of 10 Years Later had Daisuke flabbergasted while drinking, he had to make a fool of himself somehow. The chapter had the club say their friendship hadn't changed. So yeah, none of the club members could have been involved in a relationship with Daisuke, and given them reporting to Asahi-sensei about their changes. Honestly, Asahi-sensei being surprised about Daisuke's job prospects seems funny considering she stayed in contact with his mother.
If there was an endgame, and it isn't harem, these two are it. Then again, him making a fool of himself might have been a harem play that has just never worked out. Considering the girls are looking fondly at the event. . .