It seems that MC can only foucu on one girl to achieve a romantic relationship.
I have tried Charlotte, Lucy and Emma routes separately. And Emma finally starts to consider MC as a possible partner and has a wet dream in update Ep.13.
I have not tried Suzi route yet, may have a try after her return to the family.
The developer make a quiet realistic slow-burn game. Shall follow up.
The story is just like a visualised version of some good friction. I wonder why few developers just make games based on well-known frictions. Like using good stories written in Chinese, Japanese and adopting AI tool to translate them.