@genericlinic: The whole series is basically the ??? triangle of people with human relation problems.
Valerie tend to fantasizes and fail to notice reality (i.e. this whole misunderstanding mess and why she's so afraid of Serenia)
Duke has been living like a machine and never understand people's emotions
Serenia/Jia ....well, it's basically a mix of lacking knowledge and that big trauma.
Since living in isolation left her with little experience on human relations, she doesn't realize something she doesn't care others might care.
And then add in the trauma of losing her friend when she tried to care about others' opinions.
She doesn't want to regret losing someone because of worrying about others' opinions anymore so she essentially ignored any 3rd party's opinions from then on.
Which of course lead to the HILARIOUS situation of Serenia trying to honestly get closer to Valerie who try to stay away in her misunderstanding.