Wonder how will the author turned this in to a happy end, or will this go straight bad end? Though from the look, this NTR dude will probably die off in the next book as he doesn't wanted to run to live in 3rd world country, and Mizuha got drugged so hard in this book so she probably broke [her logic is already broken since the last vol with a severe case of stockholm syndrome though, feeling sympathy for the rapist who continuously rape her and drugged her and all]
Really wonder how this will end too. Maybe Taki finds the ribbon after sneaking out of the mixer, remembers Mitsuha and locates her? Then they either end up together or he abandons her after seeing her become a cockslut. Or the even more despairing scenario would be Taki going with the mixer girl to the same hotel and start fucking her in a room right beside Mitsuha's and they never realize the other is there. Cue both of them giving up on finding each oher.
@TomatoP: I though the best NTR plot will be he will meet her at the stairway like the movie. However now she is pregnant or have the baby already. The cuck guy may go to jail because his criminal act.