Sources for the information I used in the main article, and my additional two cents.
Development Starting in 2005
Bon Art Studio shows Backbone Entertainment was shopping around for a graphical team in 2005:seen here
Foundation 9 Entertainment eventually won the contract.
Konami asked Backbone to make an American Tokimemo
Konami of Japan gave support to Backbone
This Famitsu article gives a good summary: seen here
They even translated Tokimeki Memorial for him.
Konami provided some advertising support
Brooktown High Media Artwork
High quality artwork provided to magazine and online game reviewers. Good look at the development material: seen here
Brooktown High Soundtrack
Lists artists involved with the music can be found in the instruction manual: seen here
Brooktown High Changed Art Direction