Around the same time, a short anime series about Bis titled "Backstage idol Story" aired on Space Shower TV.  2013's first release by Bis was "Get You", a collaborative effort released with the idol group Dorothy Little Happy. In March came "BiSimulation" and the intention of Yurika Wakisaka to depart from the group due to health issues. Yurika was the center for the single, with a limited edition version of its CD including a photobook of her and the music video for its B-side "Hide Out Cut" devoted to documenting her time in the group. Yufu Terashima departed soon after, although her split from the group was a less amicable one: Pour Lui openly writes in "BiStory: Who Killed Idol?", her autobiographical account of Bis, that she strongly dislikes Terashima. Three new members entered the group after this: First Summer Uika, Tentenko, and Saki Kamiya. In June, this lineup of Bis released the single "Die" (featuring a B-side produced by Noriaki Tsuda of Kemuri). It reached number 6 in Oricon's weekly charts, marking Bis' first time in the top ten. As Bis Kaidan, they also released a harsh noise album. The group also appeared in Dempagumi.inc's music video for their song W.W.D II, apart from this, they had joint concerts and a single 'Denden Passion / Idol', this release was only sold at concerts. On August 15, Rio Michibayashi announced her departure from the group. A double A-side single titled "Fly / Hi" was released to commemorate her departure. In October, with the nationwide tour "Bis After All" approaching and faced with the departure of Michibayashi, Bis announced that a "JK" would be joining the group as a new member. "JK" is understood in Japanese as a shorthand slang term for "joshi kousei", meaning a female high school student. But instead, the new member turned out to be Junko Koshino, a famous fashion designer who is 74 years old. She was an active member of the group for just one week, and was appointed an honorary lifelong member on the 5th of November. On the 10th, Megumi Koshouji made her debut as the new 6th member of Bis. The group then set out on the first dates of their tour and worked towards their goal of disbanding at Budokan.