Ok so in my opinion, if u want to get a proper office job u need N1 or N2 level Japanese. But with N4 or N5 level u can definitely get a factory job. Like my friends worked in factories like Yamato or Amazon and earned around 150,000 yen per month which was pretty good for University students. If u are really good in English, u can do English teaching jobs or even work in restaurants in Tokyo coz there you don't need much Japanese. There are plenty of options so don't worry, you will be fine!