@tokyo_0 To be on the safe side, you need to be careful. Don't leave rice sitting for hours un-refrigerated. But I am Ok with keeping in the fridge for a couple of days and making fried rice with it, or freezing it.
I saw some conversations where people were being super-conservative about rice, but keep in mind that Japanese and Korean rice cookers will keep rice warm for hours, and have a reheat function. (You are in Japan, right?)
It is a bit like keeping garlic under oil. Italians have been doing it for centuries, but in the US people are obsessive about it.
In the end tho, do what you are comfortable with. I am not a food scientist or doctor.