Nu ABO

The title is a play on words meaning "New Blood Type": A, B and O are blood types, and if the letters are said in succession, it sounds like "ye-bbi-oh" ("예삐오").

The title track from the EP, "Nu ABO", was chosen as the lead single. "Mr. Boogie" was re-released as a digital single on July 17, 2010 for follow-up promotions. Live performances of both "Nu ABO" and "Mr. Boogie" were broadcast on various local music shows Music Bank, Show! Music Core and Inkigayo during the promotional cycle. "Me+U" was also performed during the 2010 Dream Concert and on Wave K with its own choreography. A remix version of "Ice Cream" by Idiotape was also released on March 27, 2013. The title track was also used for the Korean-American film Make Your Move (2013), and was subsequently included on its soundtrack.

The extended play debuted and peaked at number 2 on the Gaon Album Chart for the week ending May 8, 2010. In its second week the album fell to number 19 and to number 21 in its third week. The album rose to number 13 in its fourth week. The extended play was the 8th best-selling album in May 2010 in South Korea. It was the 53rd best-selling album in the country during 2010, with 27,281 copies sold.

The single "Nu ABO" was ranked amongst the best K-pop songs of all time by Spin at number 12, Music Y at number 87, and Melon at number 45. Stereogum included it in their 2012 list of The 20 Best K-pop Videos at number 16. It was named one of the best female idol songs since 1996 by The Dong-a Ilbo at number 5.