Do I need to use a lawyer to naturalize?

No, you don't. Anecdotal evidence suggests that most people do not use a lawyer either. Unlike many processes related to visas in Japan, there is very little that a 司法書士 {shihōshoshi} (judicial scrivener) can do for a naturalization candidate because they are not allowed to represent the person in proxy at any of the interviews or presentation of the paperwork. The case officer wants to interactively talk to the candidate, to assess their Japanese skills among other due diligence.


Additionally, it's probably unlikely the judicial scrivener will be able to help you with the hardest task: collecting all the paperwork, as most of the paperwork will be personal and private and will require your direct permission, identification, and/or communication with overseas family members that only the applicant would have familiarity with.

Now, they may be able to help you complete the forms, but to be honest, the paperwork is not a U.S. 1040 tax form; most of the paperwork is simply the transferring of data such as names and addresses to forms, which anybody that reads and writes intermediate level Japanese should be able to do. The second hardest thing to do as part of your naturalization paperwork is translate the non-Japanese language documents into Japanese. It's unlikely that your lawyer will do this for you, so you'll have to hire another person to translate prior to handing over the documents if you don't want to translate your paperwork by yourself. Finally, the hardest document to complete, the motivation essay (動機書 {dōkisho}), cannot be written by anybody but yourself. And it must be hand-written. I wrote mine using a word processor first, then transcribed it to paper longhand.

Your case worker can provide you with most of the advice you need, for free. They, after all, do nothing but work on nationality law execution with real cases from all sorts of countries all day. However, they will only be able to provide it in thirty minute chunks of time every couple of weeks. And if your case worker is like the ones in Tokyo, they will be patient with you up to a point *; meaning they may not take kindly to answering questions that are already clearly answered in the thorough guidance book they provide. And if you ask too many questions that are already answered in the booklet you receive, your case worker may suspect that your Japanese reading comprehension is not that good and decide to do a level check.

* For those doing the process in Tokyo: the main interview room at 九段下 {Kudanshita} is divided into eight separate work rooms where eight candidates are processed simultaneously. The partitions are mere particle board and don't reach the ceiling and only a curtain separates you and your case worker from the rest of the room. Because of this, you can hear the conversations everybody else is having. While my conversations were pleasant, I was able to hear the other candidates asking questions, and even I recognized that some of them were wasting their case workers time by providing incorrect paperwork or asking. The case officers weren't abusive or mean to these people, but they made it be known that the candidates were wasting both of their time by being unprepared.

If you are still interested in hiring a judicial scrivener, you can get more information at The Japan Federation of Shiho-Shoshi Lawyer's Association. Talking with one, excluding paperwork and actual work, can run about ¥10,000 an hour.