Updated 12/5/2012: Novel synopsis and cover image added
Shirogane Naoto will be the main character in this spin off novel (tentative title), set to be released in Spring 2012 by Dengeki Bunko. Shirogane fans might be interested as it may shed some light onto Naoto's personal life, tho not much about the novel is revealed at this point of time.
More info will be revealed later on.
Dengeki Bunko has released more information regarding the upcoming Naoto-focused novel, along with a tentative image for the front cover of the novel, titled;
"Persona x Detective Naoto".
Rough synopsis translation
"Taking place 1 year after the Persona 4 incident, Detective Prince Shirogane Naoto's cooperation is requested on an investigation on the bizarre disappearance of an old detective friend, Aoi Touko, leading him to visit Yagokoro City.
However, Naoto has unexpectedly ended up with a quickly assigned partner. His polar opposite adolescent partner, Kurogami Sousei has introduced himself as "mechanized"!?
This uneven combination of cool implusiveness has lead the investigation to a surfacing website that calls out, named the "Mayonaka Site"... "