"∞2" (read "Infinity Ni"; translated as "Infinity 2") is Do As Infinity's 23rd single, released on June 16, 2010. The single is the second in the "Infinity" series, after Do As Infinity's 21st single "∞1" (2009). Like "∞1", "∞2" contains four songs with none named after the single itself. Between September 1 and October 31, 2009, the second installment of a contest called Do! Creative!! was held to give Do As Infinity fans a chance to compose songs that the band would later perform.