Ado, who previously delivered the powerful theme song for the Doctor X drama series, is once again taking on the role of theme song artist for Doctor X: The Movie, set to hit theaters on December 6. The new song, “Episode X,” was written by Ayase, the acclaimed Vocaloid producer and member of YOASOBI, marking their first official collaboration.

The film, which expands on the beloved medical drama Doctor X: Surgeon Michiko Daimon, will follow Ryoko Yonekura’s character, Michiko Daimon, a fearless freelance surgeon known for taking on seemingly impossible cases and never failing. Ayase’s dynamic and fast-paced melody complements Michiko’s unyielding resolve, capturing her essence as she tackles challenges with sheer determination.

Ado shared her excitement about this collaboration, stating, “I’m thrilled to be part of the Doctor X world again. Working with Ayase on ‘Episode X’ is especially meaningful, and I hope listeners notice how much I’ve grown since singing 'Ashura-chan' for the drama.” Despite having covered several of Ayase’s songs in the past, this marks their first official collaboration on a new track.

Watch the MV for Ashura-chan:

Ayase reflected on the inspiration behind the song, saying, “As I explored Michiko Daimon’s backstory, I couldn’t help but see similarities between her and Ado. Their energy and determination are what guided me in creating this piece.”

Ryoko Yonekura, who has portrayed Michiko Daimon throughout all seven seasons of the drama, also praised the song, noting, “Ado’s unique world of sound aligns so well with Michiko’s lone wolf nature. It’s a song that exudes strength and courage, just like Michiko herself.” She also mentioned that the track evokes the bond between Michiko and other characters in the story, adding even more emotional depth.

Directed by Naoki Tamura and written by Miho Nakazono, Doctor X: The Movie brings back the iconic team that has made the series a household name since its first broadcast in 2012.