9nine originally formed in 2005 with nine members, but after many graduations and the addition of new members, the current five member lineup has remained since 2010. Satake Uki and Nishiwaka Sayaka are the only remaining original members in 9nine - Nishiwaka Sayaka is also the younger sister of Perfume's A-chan.
Since their formation, the group have released a huge number of singles, digital releases and four major albums as well as participating in magazine shoots they are known for their work as actresses and regulars on variety shows. Their music started out as cute and playful, however as the group matured (and moved to Sony Music Japan in 2010) they have changed direction towards more serious ballads and dance tracks.
"With You/With Me" is their 16th major single and was released earlier this month in Japan.
You can check out the very cute, pink and pastel-coloured MV for "With You/With Me" here via Jpopsuki TV.