Is Recently, My Sister is Unusual coming back?

No — Recently, My Sister is Unusual ended on March 22, 2014, on Tokyo MX.

It was a comedy anime series that premiered in 2014 and was based on a romantic premise. The story followed Mitsuki Kanzaki, who lived with her step-brother Yuya after her mother remarried. The series involved a supernatural twist when Mitsuki was possessed by the spirit of a young girl named Hiyori Kotobuki, who needed to fall in love with Yuya to reach the "Gates of Heaven." The show explored their interactions and romantic misunderstandings within a humorous context.

The cast included Chinami Hashimoto as Mitsuki Kanzaki, Yui Ogura as Hiyori Kotobuki, and Hisako Kanemoto as Yukina Kiritina. The series aired for a single season, with a total of 12 episodes, each approximately 25 minutes long.