ONF, ‘Great Song restaurant’ is igniting the comeback fever by opening its first teaser image.

On July 21st, the group's agency WM Entertainment released the first teaser image of its summer pop-up album "POPPING" through ONF's official SNS channel.

The posted teaser image reveals a thermometer engraved with ONF's logo against a refreshing sky blue color in the background. The temperature shown in the thermometer is about 38 degrees, an indication of a midsummer heatwave, while the thermometer's mercury is in clear blue color, contrasting the temperature and raising curiosity with its unique mood.