|Mizuki Fudou||19||Tokyo||Sunlight Party|
|Sachie Kondou||23||Toyama||Heroines Party|
|Ume Momoi||16||Kanagawa||Bishoujo Party|
|Yami Ringo-sama||15||Aomori||SOS Party|
|Mika Kozuru||17||Kagoshima||Subculture Party|
|Natsuki Hoshina||16||Niigata||Heroines Party|
|Shizuka Onimaru||16||Fukoka||Heroines Party|
|Kuruha Amou||13||Tokushima||Wakaba Party|
|Sakurako Iizuka||18||Nara||Starlight Party|
SMILE ♥ X was formed as a rival group for the veteran idol group Cherry 7, who were working with the Rougai Party to end the practice of idol Diet-women. The group was a collaboration between all the current idol diet-women, proposed by Shizuka Onimaru. All the current idol Diet-women audition for a role in the group and Mizuki Fudou chose the final 9 members.
SMILE ♥ X and Cherry 7 competed against each other and SMILE ♥ X (without Natsuki Hoshina) earned the support of the Japanese public, winning the contest, but were unable to stop the passage of the Idol Diet-woman Prohibition Bill.
Each girl wears a matching yellow dress wih frilly white detail to match the fabric covering the chest. They also wear frilly wrist accessories and boots with a pair of knee-socks with a blue ribbon sewn to the side to match the blue accenting of the outfit. On the lower right corner of the top and upper left corner resides a black clover ornament. Each girl also wears a white and yellow cap with a ribbon sewn to it. The ribbon is colored to match the sash draped around her right shoulder and chest.
- The Heroines Party is the party with the most members represented in SMILE ♥ X (and is the only party which all of its current members passed the audition).
- Natsuki Hoshino was absent from the group's debut performance. The remaining members wore hats with ribbons in her member color (red) rather than their usual colors in her honor.
- Every Party featured in Idol Jihen has at least 1 representative in SMILE ♥ X, except for the Rougai Party.
- The average age of this unit is 17 years.
- Sachie Kondou and Shizuka Onimaru are the only members whose official colours don't match the official colour of their Party.