Song title: ウェアイズマイヘッド★ばんきちゃん (Where is my head★Banki-chan)
The album was a joint release between ほりっくさーびす (Holic Service) and ばーどちゅーん (Birdtune). I can't track down the title (maybe it was never released?), but it was supposed to be their C85 album.
Arrangement: KuKuDoDo Vocals: nanano Original song: 柳の下のデュラハン (Sekibanki's theme from DDC) Lyrics Original Niconico video
