WM-0697~8: Tokushu Houdoubu original soundtrack

[Secret Squirrel]

I don't think we know the BGM composer, but there's this:

制作には、アドベンチャーゲーム「流行り神」のスタッフが、ゲーム本編で流れる楽曲の制作は、『うたの☆プ リンスさまっ♪』や、『魔法少女リリカルなのはA's』等で有名な『Elements Garden』が担当しています。

The sentence is pretty complex though, so I don't know if they are indicating the Staff of Hayarigami, or even Elements Garden.

[Cedille]

The sentence means the development of the game is by the staffs of Hayarigami, and BGM by Elements Garden.