I like that the author’s trying something different, although the whole “Chris’s brother” subplot falls flat when you only mention it in bits and pieces.
At this point , I rather have the brother and the Small fry be part of the Kanji household. Chris has a family member and there are more hands to help the farm.
@Fushiginiku remember the previous chapters. By the time Chris arrived to Japan, she was already a ticking timebomb full of pathogens and the Japanese government had to deal the problem.