Tsubasa is truly a remarkable manga. It is a masterfully written piece that features charming characters and takes readers on an exciting journey. This manga stands as one of CLAMP's greatest works to date. It is a manga where one needs to have read most, if not all, of CLAMP's previous works to fully understand the references scattered throughout.
As a whole, this series is outstanding. The first volume, in particular, is simply wonderful and endearing. Syaoran and Sakura, the main characters from Cardcaptor Sakura, inhabit a fantasy world where Sakura is the princess of Clow Kingdom and Syaoran is an archaeologist. They both encounter these ruins (not simultaneously), and Sakura loses her feathers, which are her memories of her life. With her feathers dispersed across different worlds, Syaoran embarks on a quest to find them and save Sakura's life.
There are also several colorful characters who accompany him. Firstly, there's the grouchy swordsman Kurogane, who was the guard of a princess and was sent on a journey to find a way to be strong without taking the lives of others. Then there's Fai, a powerful sorcerer who appears to be fleeing his world for some unknown reason. He is positive, cheerful, mischievous, quick-witted, and a bit of a goof. The comedy between him and Kurogane is highly entertaining. It's the typical opposite personalities who hate each other but are really close friends dynamic. While it's funny at times, it's also something we've seen before.
Of course, this series is connected to CLAMP's other series XXXHolic. The characters visit the Dimensional Witch Yuko Ichihara, and she sends them on a quest while each of them pays a price for undertaking this journey.
If I had to offer one criticism, it would be that Sakura seems rather weak in this series. She is unconscious for a significant portion of the volume (and some of the earlier volumes as well), and her true love has to rescue her constantly.
I absolutely adore this manga. It's fun, clever, creative, and the characters are a joy to follow. It's a wonderful adventure filled with fantastic magical moments.