A certain English teacher who teaches at a university once asked me if she was eligible for permanent residency although she has not stayed in Japan for 10 years yet. Staying in Japan for 10 years is one of the requirements for permanent residency, but there are some exceptions.
If the person is a highly skilled professional, for example, the required length of stay is shorter. Facts such as the educational background, vocational experience and annual income are taken into account. Points are calculated on the basis of these, and if the person scores a certain point or more, the person can be eligible.
Please feel free to inquire if you think you are eligible even if you have not stayed in Japan for a decade. I will take your circumstances into account and carefully check and see whether you are eligible.