46. Do any other restrictions on online media advertisement (beyond limits) exist?

Source: 
公職選挙法, 1950 (2022改正)
Public Offices Election Act, 1950 (as amended by Act No.68 of 2022)

第百四十二条の六　何人も、その者の行う選挙運動のための公職の候補者の氏名若しくは政党その他の政治団体の名称又はこれらのものが類推されるような事項を表示した広告を、有料で、インターネット等を利用する方法により頒布される文書図画に掲載させることができない。

Article 142-6 No person may cause advertisements displaying the name of a candidate for public office for whom that person is conducting an election campaign, or the name of a political party or other political organization, or any matter that could be inferred to be such a name or organization, to be placed in documents or illustrations distributed for a fee by means such as the Internet.

Parties and candidates are banned from buying online ads to display candidates' names.