I came across this Candies（キャンディーズ）song with a bit of spice when I was exploring this compilation album titled "Utahime Chronicle 1968-1984"（歌姫クロニクル~1968-1984~...Songstress Chronicle）. Exploding out of the gate with this brass that sounds as if it were introducing a super sentai series, "Heart no Ace ga Detekonai" (Show the Ace of Hearts) was Candies' 8th single from December 1975.
With lyrics by Machiko Ryu（竜真知子）and music by Koichi Morita（森田公一）, "Heart no Ace ga Detekonai" is one woman's determined efforts to get that man of hers. Considering that it was released a few weeks before Christmas, perhaps the song had that much more oomph since I think the Yuletide in Japan has as much (or even more) of a romantic dimension as Valentine's Day. One can only imagine what might happen nowadays at a bonenkai where the alcohol is liberally flowing.
The song made it as high as No. 11 on Oricon and finished 1976 as the 87th-ranked song. It was also a track on Candies' 6th album from April 1976, "Haru Ichiban"（春一番）. Of course, the trio's following single with the same title as the album would become one of their signature songs.