Mitsui Aika (光井愛佳) is a Japanese pop singer. She was a member of Morning Musume (モーニング娘。), joining as a member of the eighth generation from the audition in Japan during December 2006. At first she was the only member of her generation, but she was later joined by Chinese members Junjun and Linlin. After suffering a leg fracture, she was unable to keep up with a new dance oriented Morning Musume, and graduated alongside Niigaki Risa.