The "nation's singer" and "nation's little sister," Jo Young Nam and IU, have come together for SK Telecom's "T-Store" application CF! The two sang a duet of Jo Young Nam's own hit track, "Perianth Marketplace", as the advertisement's main theme song, only there was a slight change in the lyrics:  "Come and check it out~ The place where customers come~ Application marketplace~ There is nothing that you can't find~ T-Store." The CF was also created in celebration of the T-Store hitting 170 million in downloads. In order to express the diversity of their T-Store, IU and Jo Young Nam made various transformations into DJs, reggae singers, Chinese restaurant chefs, beautiful ladies, and 20 other roles. IU even used her famous 'three high notes' in the song, showing off her impressive vocals once more under the support and direction of senior Jo Young Nam. Source: Kyunghyang via Nate