Is it okay to exit Japan a few weeks after arriving on an Engineering/Humanities visa?

I recently arrived in Japan about a week ago on an Engineering/Humanities visa, and I am planning to leave in December for a three week trip, with my employer’s approval to return afterward. What do I need to prepare to make sure I can come back to Japan? Will immigration in Japan or in my home country question my departure and return?

by Ecurious5021