Aa Ii na! (あぁ いいな!; Ah, How Nice!) is the second single released by Japanese pop duo, W. It was the first original release by W, as all their previous songs had been covers. The single was released on August 18, 2004 under the Zetima label. In the music video for "Aa Ii na!", W are supported in dance scenes by Berryz Koubou who act as back-up dancers in both "Aa Ii na!" and their next single, "Robo Kiss". The single sold 41,581 copies in total, making this their highest selling single.