Yuma and Yuuhou have power of "Couple" - when they in close body contact, both see terrible events from near future. Yuma's power is to receive prophecy of how to avoid bloody final and Yuuhou's is to manipulate future by Yuma's prophecy. So, in order to prevent catastrophic events what are coming, they must have... say, very close body contact. Kudan-sama - mysterious short person who seems to be source of Power of Couple - and Yuma's mother (bakunyuu-type) hence urge them to do that. The problem is Yuma and Yuuhou are actually cousins and both prefers to avoid these... contacts. Especially close ones.
Kudan No Kanojo To Mirai Koukan - Raw Chapter 11
Kudan No Kanojo To Mirai Koukan - Raw Chapter 12