Mafia x Family [Chuuya x Yor reader]

Chuuya Nakahara the Mafia who works for Mori got a mission to go to the other side of the country and kill Donovan Desmond before he made a war between the two countries 'Westalis' and 'Ostania'. But before he could do that he has to make a fake family and send his child to Eden Academy and make friends with his son Damian Desmond and this pissed him off... have a family and send his child to Eden Academy and get close to Donovan's son... and do a fake marriage?!... this was pissing him off.
After saving a little girl named 'Anya' from the lab he gave her the entrance exam she pass but there was a problem a child should attend the second exam with both parents but he doesn't have a wife. One day in the tailor shop he meets a beautiful girl but she was familiar to him and then it hit his head it was his childhood friend (let's just say his crush) '[Name] {or Yor} Briar who saved him from the police when he was 15. He asked her if she could be his fake wife for his mission and she agreed.

As months go by Chuuya started to like his fake family and develops more feelings for [Name] {or Yor} but he knew that this was going to end soon. what happens next?
(btw I'm not dazai x Chuuya shipper)