Synopsis:

A 4 part OVA will be released with limited editions of the Tsubasa and xxxHOLiC volumes.
There will be two OVAs for each series, with plots linked together.

The material they’re covering will be the Nihon Country Arc and scarcely some of the Celes Country Arc.

The first part of the OVA will be available with a special edition of volume 26 of the Tsubasa: RESERVoir CHRoNiCLE manga.