How long does it take for a utility model application to be granted in Japan?

yes

• Grant fee: The applicant shall pay the granted fee within 30 days after receiving the granted notice.
• Annuity: The annual fee for the first to third years must be paid together with the application fee when the patent application is filed, and the annual fee will be paid year by year from the fourth year, and the payment period corresponds to the granted date. 200% of the year's annual fee paid within the month is a late fee.

Japan Patent Office

English: Japan Patent Office, abbreviation: JPO

Website: Japan Patent Office (jpo.go.jp)

Japanese Invention Patent Search: Japan Platform for Patent Information｜J-PlatPat [JPP] (inpit.go.jp)

yes. Within 3 years from the date of application, or within 3 months from the date of receipt of the rejection decision, the patent type can be changed from design to invention/utility model at the request of the applicant.

A conversion fee shall be paid for patent type conversion. Once the original patent application is converted, it will be deemed withdrawn.

The JPO conducts formality examination and substantive examination of invention patent applications. The applicant should submit a request for substantive examination within 3 years from the filing date. The JPO makes an granted decision if it determines after review that no grounds for refusal have been found.

• via Paris Convention : 12 months from earliest priority date.
• via Nationalization of PCT : 30 months from the earliest priority date.

Inventors have a novelty grace period of 12 months after disclosure (including sale).

25 years

• via Paris Convention : 6 months from earliest priority date.
• Hague Agreement route: 6 months from earliest priority date.