A1 YMO Comment
A2 YMO Spot
A3 Kageki na shukujo (karaoke)
A3 includes all of the backing/harmony vocals throughout so is very similar to the regular version.
This flex-disc was a competition prize; entry postcards were included in early pressings of the album Naughty Boys (Instrumental) = 浮気なぼくら (インスツルメンタル). According to Japanese sources there were 250 copies pressed but this figure is doubted by collectors as it was apparently quite easy to get hold of at the time of release.