1. A nucleic acid complex, comprising: a first nucleic acid molecule, a target recognition sequence, and a second nucleic acid molecule arranged in 5′ to 3′ direction of the nucleic acid complex, wherein the first nucleic acid molecule comprises a nucleotide sequence of SEQ ID NO: 2 or SEQ ID NO: 3, and the second nucleic acid molecule comprises a nucleotide sequence of SEQ ID NO: 4, and the target recognition sequence is 10 to 40 nucleotides in length and complementarily binds to 10 to 40 consecutive nucleotides of a nucleic acid of interest.