Norio herself said somewhere back when Kana and Sota were first shown working together that the two would not be a couple. I forget where I read it but I think someone had pasted a Tweet response to a question into the comment section for one of their chapters.
Still not sure if it's Jin Sota or Sota Jin so I've been assuming Sota is his given name. I record names as Family, Given in my notes and prefer to use given names when discussing characters and to use Family Given as full names as in Ichikawa Kana (since they are Japanese).
These are my BokuYaba notes on the parents. We don't know if they hooked up while she was still a student.
Ichikawa, Yusaku (M)
o) Age 60 (59 at Ch 64.2)
o) Kyoutarou's father
o) University professor
o) Does not drink
Ichikawa, Yumiko (F)
o) Age 47 (46 at Ch 64.2)
o) Kyoutarou's mother
o) Works part time at a drug store
o) Thinks highly of Anna
o) Met Yusaku while a student at a woman's college