Dealing with Police

https://www.reddit.com/r/japanlife/comments/1438h3q/stopped_and_forcibly_drug_tested_in_shibuya/
 

They legally can’t do anything if you refuse to cooperate, except for maybe the ID (circumstances might make that illegal too but it’s iffy).

Shokumu shitsumon (Questioning) are defined in the Police Duties Execution Act Article 2, subsection 1. They have to have probable cause. Then also you’re within your rights to not be searched without consent. Technically even if you flee it’s not illegal at this point, although they would chase you.

Always record the police and report them to the 公安委員会, or the Public Safety Commission. You can also sue them for infringement of rights.

https://www.japaneselawtranslation.go.jp/en/laws/view/4043/je

The ID thing is defined in the Immigration Control and Refugee Recognition Act, Article 23 Subsection 3 states that you have to present ID when requested during the duties of police officers (among other officers mentioned). Illegal questioning is not within their duties, but I personally think it’s hard to refuse this one, since nationalized people don’t have that limitation to their rights.

https://www.japaneselawtranslation.go.jp/ja/laws/view/3624

Edit: someone else said to ask for their police ID (警察手帳). Police are obligated to present it under the 警察手帳規則　第5条 or Article 5 of the Regulations for Police Badges (not an official translation).

https://elaws.e-gov.go.jp/document?lawid=329M50400000004

Sorry I can’t find the English version for this one.

Edit 2: On search warrants and seizure and search:

Japanese Constotution Article 35, on the right to not be searched.

https://japan.kantei.go.jp/constitution_and_government_of_japan/constitution_e.html

Immigration and ID exceptions as stated above.

Police Duties Execution Act Article 2 subsection 1, 3, and 4 adds details to what they can do during questioning, and on arrests and detainments as stated above.

Code of criminal Procedure Article 218 on exceptions to that rule on warrants. (Search warrants and arrest warrants)

https://www.japaneselawtranslation.go.jp/ja/laws/view/3364