Nine-chan's feed

I just read this from ch 1 so like everything is this fresh on my mind. I remember that ritsu said that he was on a mercenary group before being recruited and that he was part of it since he was a child. And he looks like 3-4 yrs old on that panel and it also looks like he was taken care of ish by his former co-members so how the heck does is he like 8-11 yrs old when taken in by the group. Also where is the mc's mother??? She was literally shown only on chapter 1 never to be seen again even when the twins were born.