Kids custody

Hi every one i need an information me and my husband has most of the time fights and we have kids which are still very young―i am tired of the fights on very small small issues i report to the police but i don’t want yo put him in jail bcoz we have kids now i decide it to contact to the lawyer and we can make a paper like that if suppose he want to seperate from me then kids will come in my custody and i will take care of kids and same for him if i want to seperate from him or wanna get divorce from him then he will be the one who will take care of kids its just for that we bound our selfs and i knew it he love his kids its just for that that he will become responsible and stop fighting on small issue other then kids are small and i m the mother i am sure kids will come in my custody but i want that they will grow up with me and my husband i don’t want that it will grow up with out father or mother ―- i want any contact number of lawyer in nagoya area or some one help me regarding with my matter plz