In Episode 10, which itself is called "Full-time Employment is a Loophole in the Law to Make Wages Lower…" or 「正社員ってお給料を安くするための法の抜け穴...」 「Seishain tte Okyūryō o Yasukusuru Tame no Hō no Nukeana 」 (essentially taken from the dialogue)…
When referring to why Nene can't work as a playtester on weekends, they discuss:
Aoba: Why can't part-timers work on the weekends?
Kou: Oh, it depends on the company, but they're paid by the hour, so if they worked overtime and weekends, they'd get paid more than you, Aoba.
Aoba: W-Wait a minute! Is being a full-time employee just a loophole to make wages lower?
Kou: We can talk about that some other time.
What is this referring to? Is this something that also applies to the western world or some kind of business law in Japan?