Apply for naturalization at the Legal Affairs Bureau, not at the Immigration Bureau.
Since it is under the jurisdiction of the Ministry of Justice, it is the Minister of Justice who issues the permit, but the window for accepting applications is different.
Japan does not recognize dual citizenship, so if naturalization is recognized, you will have to take steps to abandon your existing nationality, which is a high hurdle for your application.
One of the requirements for naturalization application is Japanese ability.
Interpretation of Japanese proficiency is quite different depending on the Legal Affairs Bureau, and some Legal Affairs Bureaus require that the Japanese Language Proficiency Test Level 3 be okay, while others require it up to the Japanese Language Proficiency Test Level 1.
At the first consultation, the Legal Affairs Bureau will listen to you and give you instructions on the necessary documents, and you will be asked to write a questionnaire at the reception in front of you to determine your Japanese proficiency, and your Japanese proficiency is still insufficient. There is also a Legal Affairs Bureau that pays in advance if it is judged.
There are various ways to do it depending on the Legal Affairs Bureau. Since the jurisdiction of the Legal Affairs Bureau is divided by address, it is difficult to select and apply for the Legal Affairs Bureau, which does not examine Japanese proficiency very rigorously.
帰化申請は入国管理局ではなく、法務局で行います。
同じ法務省管轄ですので、許可を出すのは法務大臣ですが、申請を受け付ける窓口が違います。
日本は２重国籍を認めていないので、帰化が認められれば今までの国籍を放棄する手続きをしなければならないので、その点がハードルが高い申請です。
帰化申請の要件の一つに日本語能力があります。
日本語能力は法務局によって解釈がだいぶ分かれていて、日本語検定３級程度でもなんとか大丈夫なところと、日本語検定１級程度まで求める法務局もあります。
初回相談でまずは話を聞いてくれて、必要書類の指示をしてくれる法務局や、受付時の質問票を目の前で書かせて日本語能力を見極めて、日本語能力がまだ足りないと判断されたらそのまま門前払いの法務局もあります。
法務局によってやり方がいろいろとあります。法務局の管轄は住所で分かれるので、日本語能力をあまり厳しく審査しない法務局を選んで申請ということができないのが難しいところです。
