Additional details about the magazine are found in the Monthly Corocoro Comic issue that released today. More information will be posted on their official X account shortly along with more information leading up to the December 19th release.

Corociao magazine is a new joint manga magazine between the Corocoro and Ciao magazines. Both are published by Shogakukan. Corocoro's target demographic is school-aged boys, while Ciao is aimed at girls. This new magazine is to bridge the best artists between both in this new universal magazine.

Hiroyuki Takei previously was serialized with Corocoro with the "Hyper Dash! Yonkuro" manga which is still on hiatus and is one chapter away from completion.

He was also working with Yuki Imada on the "MINI4KING" manga which has completed.

Story (rough translation, and names subject to change)
In the near future, the existence of spirits has been confirmed, Shunsaku rides a magic-powered robot to fight against evil spirits.

The purchase form is now open for fans in Japan for a limited time (no international shipping):

New Shaman King Flowers episodes will air each Monday. Tuesday through Friday will air Captain Tsubasa and My Deer Friend Nokotan.

Full press release in Portuguese:

Each volume is priced at $10.99 USD. All volumes are not resellable and not downloadable.

A placeholder page for Shaman King The Super Star is listed but does not have any volumes available. The original Shaman King series is also not listed on the service.

Some additional examples for comparison.
You can see the full chapter in Japanese here: shonenjumpplus.com/episode/1710...