This design features the illustration of the front cover of the song- art book Himitsu Stranger. The song-art book Himitsu Stranger is based on the lyrics from 13 songs recorded by Masamune Kusano for the Spitz album "Himitsu Studio". Artist junaida illustrated the lyrical stories for each of the songs. It has "butterfly stopper" pen holders, which also function as a clasp to keep the cover shut.