There's this rumor on Japanese blogs and BBS telling that Hina new solo CM is actually for a JR West CM with Hitotsu no Uta as its theme song. The product is said a train passcard or something like that. While the upcoming Kanjani8 single will be used as ROMES theme song.
Again, this is only rumor. Sorry if it's not correct. Just want to give something for some eighters curious soul.