Well the idea is for the story, what if kaiju no 9 survived the final battle by crawling out from the remnants of the Meireiki era kaiju?
Escape from the Defense Force using teleportation but faulty due to his damaged core, he accidentally arrives in erma universe, disguise as Kanji Nagamine (one of his human disguise), meeting yori (emiko sister).
Became her husband the twins biological father in this timeline, they inherited his kaiju abilities. No 9 even creates small kaijus as pets and guardians for his family home, even when sometimes he felt pain from his damaged core does not heal properly from old final battle.
This often people mistake him for suffering from a heart attack he just explained that just his heart condition never heal properly from long time incident in his past.
