Raito: Tanaka Yu, you must marry Kyoko or the future will suck, because superpower virus.
Yu: Wait what
Marionetter: No, sleep with my mind-controlled women to cause the virus!
Yu: uhh no
Kyoko: Raito's an undercover detective? It all makes sense now!
Asuka: I'm a distraction!
*shenanigans as Marionetter and other evil time travelers try to get Yu to sleep with girls, failing each time*
Koyomi: I'm Yu's other childhood friend!
Raito: (Shit, she's the girl he married in the original timeline)
Yu: Sorry, I like Kyouko
Koyomi: Understandable, have a great day. (cries)
*more shenenigans, infighting among the evil dudes, most of them die*
Teleporter: I figured out how to manufacture the virus from Tanaka's DNA!
Asuka: Surprise, bitches, I was Marionetter all along! *kidnaps Kyouko*
Readers: That twist literally contradicts established events from volume 1
Teleporter: Nah, we don't need to mess around with them anymore. *kidnaps Asuka* I just want your future dad's money
Raito: Quick, confess to Kyouko before he releases the virus!
Yu: Kyouko I love you forever! Please marry me!
Kyouko: Yes!
*Raito, Asuka, Teleporter are yeeted out of existence*
*The timeline adjusts so that none of the crazy stuff happened but Yu and Kyouko are still together*
Epilgue: *Yu somehow retains unconscious dream-memories of the whole thing. He and Kyouko name their first children after Raito and Asuka.*