RIIZE is getting ready for an exhilarating comeback with a new prologue single.

On April 11, the popular boy group rolled out new 'Days in Lisbon' teaser photos where the members enjoy a leisurely vacation in the capital city of Portugal. In the photos, the members are seen hanging out with one another while enjoying the warm weather.

Meanwhile, RIIZE will be releasing their prologue single 'Impossible' on April 18 at 6 PM KST.