Exactly. We may raise an eyebrow at the situation, but, in the end, it's just a plot device and nowhere near as far-fetched or game-breaking as some make out.I am still not sure why this is an issue, but there are a lot of reasons a physician may not have a lot of disposable income. True, most U.S.-based physicians make a more than adequate income. But it is clear that the author is from Germany, the setting may be intended to be the U.S. or some non-descript neutral place, but the influence of Germany is strong (they call it 'football'). The living conditions in other places are not always easy to determine, especially broken down by occupation.
Physicians have enormous student loans. Many of them have to work for a good amount of time before they pay them off and are able to purchase their own practice. This family has two college-aged kids which is a major expense. And Nojiko raised them on her own, assumedly while going to a university to obtain her medical degree.
Again, I don't see why this matters. The point being made in the story is that the MC and Nami are not at the socioeconomic status of many of their fellow students and love interests. That is all that is necessary in order to enjoy the story as told.
Not everything in this game is U.S.-centric. Without implicit mentions in the game - Nojiko could work at a State-run hospital or a private hospital under a socialized health system or a privatized health system. Her salary as a doctor ('none of this unsubstantiated 'specialist' bullshit) is unknown. She may or may not have taken on student debts (bearing in mind we know little about her family or parents or past life). The MC and Nami's tuition may be expensive or it may be State-subsidized/free. Nojiko may own her home outright, or have a mortgage, or rent. Nojiko's reasons for living somewhat modestly, compared to her social circle revealed in Ch 5, are unexplained.
ONLY Ocean can answer these questions at this point.