Minutes follow monetary policy board meetings with a four to five week lag. For example, minutes released on June 19 were for the meeting held on May 21 and May 22.
Investors who want a more detailed description of Bank of Japan opinions will generally read the minutes closely. The MPB may issue a statement after its monthly meeting but the minutes will be much more detailed. In particular they will reveal who voted for and against the Committee's decisions and provide a more detailed description of the MPB's thinking. As such, the minutes are a market mover as analysts parse each word looking for clues to future policy.
Once Every 3-4 weeks.