Nanae Takahashi
After leaving Triple Tails, Shirai, though still billed as a freelancer, effectively made World Wonder Ring Stardom her new home promotion, making her debut on August 14, 2011, when she teamed with Nanae Takahashi to defeat Yoko Bito and Yuzuki Aikawa in a tag team match, pinning Aikawa and afterwards challenging her to a match for the Wonder of Stardom Championship. Shirai continued to team with Takahashi the following month, before unsuccessfully challenging Aikawa for the Wonder of Stardom Championship on September 25. On October 10, Shirai and Takahashi entered the Goddesses of Stardom Tag League. When the tournament concluded two weeks later, Shirai and Takahashi finished with a record of one win and two losses and did not advance in the tournament. In January 2012, Shirai formed the Planet stable with Arisa Hoshiki, Mayu Iwatani and Natsumi Showzuki. On March 4, Shirai produced her own independent event named "Carino!", which celebrated her fifth anniversary in professional wrestling and during which she officially aligned herself with Stardom, ending her freelancing days. In the main event of the show, Shirai teamed with Dark Angel, whom she had befriended during her time in Mexico, to defeat Miho Wakizawa and Nanae Takahashi in a tag team match. On March 25, Shirai unsuccessfully challenged Natsuki☆Taiyo for the High Speed Championship. On April 22, Shirai, Arisa Hoshiki and Natsumi Showzuki of the Planet stable made it to the finals of a six-woman tag team tournament, set to determine the number one stable in Stardom, however, there they were defeated by Nanae Gundan (Miho Wakizawa, Nanae Takahashi and Yuuri Haruka).