@17Serenity Wakaba killed and decapitated Kiriko to make it seem like it was Wakaba who had died in the church. The police wouldn't be able to identify the corpse without the head, and the DNA analysis would take some time, before which Wakaba and Odagiri would be able to escape the village - at...
@thefirst1 Nope, there are no answers to any questions raised in K37. In fact, there was no indication that the series after Returns would be after a timeskip.