This week's issue of Famitsu in Japan features an interview with Hashino, where he confirms that his development team is currently focusing on the next numbered game in the series.
Persona 3 and Persona 4 art director Shigenori Soejima has been submitting sketches for the new title, which Hashino says is making progress.
Hashino added that he is also collaborating on a separate project, though it is too early to announce anything on it yet.
The most recent game in the series Persona 4 released on PlayStation 2 in 2008. A remake titled Persona 4 Golden - featuring an online rescue mode and additional enhancements - will release this fall for PS Vita.
Persona 4 Arena, a fighting game based on the series, released this week on Xbox 360 and PlayStation 3 in North America.
A European release will follow on September 7.
Watch the trailer for Persona 4 Arena below: