There is one unspoken rule in the music market: top tier idol groups adjust their comeback dates in order to avoid direct competition. But what happens when the nation's favorite idol groups stage their comeback on the same date, at the same time? No more dull comebacks! No more shying away from direct competition! It is now time for these idols to battle it out in this unprecedented 'comeback war'.

• Taeyeon
• Lee Yong-jin
• Hyolyn
• Kim Min-young
• Nam Yu-jeong
• Hong Eun-ji
• Lee Yu-na
• Eunha