the ''
Tsubasa Reservoir Chronicle'' manga!
criminally underrated - highly recommend!
studio CLAMP's art is crazy good and the story itself is amazing.
the manga starts off somewhat slow but by volume 16 (28 in total) i could not think about anything other than reading the next chapter.
the series also has a crossover series called ''xxxHOLIC'' which just makes it even cooler.
if you read/watched other works of studio CLAMP like card captor sakura for example u will be pleasantly surprised to find easter eggs etc.
id advise you to keep your hands off the anime.
it ends before the story properly kicks off and doesnt really catch the same vibe the manga has at all.
STORY (pretty much explains how it kicks off - so SPOILERS for the first few chapters):
''The famous CLAMP bring the characters from all their creations into an ultimate showdown in this multidimensional tale.
It's the story about four travelers bound by fate and prophesied future. Sakura is the princess of Clow Kingdom, which is ruled by her older brother, King Tōya. Her childhood friend Syaoran is a young archaeologist. Sakura is revealed to have strange powers when she has a vision of a mysterious symbol and places she has never seen. Meanwhile, Syaoran discovers the same symbol at the ruins he is excavating. He sees Sakura standing on the symbol on the ground. Ghostly wings appear on her back and a mysterious force begins to pull her into the walls of the ruins. Syaoran rescues her in time, but her wings disintegrate into feathers, which are scattered across dimensions. The High Priest of Clow Kingdom, Yukito, immediately realizes that Sakura's "feathers" were the manifestation of her soul and memories; without them, she will die. In order to save Sakura, Syaoran must journey to retrieve her wing's feathers, the fragments of her memories.
Yukito sends Syaoran and the unconscious Sakura to the Dimensional Witch, Yuuko, who is one of the main characters in xxxHolic. There he meets Kurogane, a rough-mannered ninja banished from his world by Princess Tomoyo, and Fye, a magician who fled his world to avoid King Ashura. Each of them must pay with what he values most in order to gain the power to cross dimensions. For Kurogane, it is his sword Ginryū, and for Fye, it is the tattoo on his back which regulates his control of his magic. Syaoran, on the other hand, must pay with his relationship with Sakura: even if he is able to retrieve all of her memories, she will never remember anything about him or their relationship. (This sacrifice also pays Sakura's "toll" to Yuuko, because what Sakura values most are her memories of and with Syaoran.) Only when the three agree to her terms does Yūko present them with the power to cross dimensions; a white creature named Mokona Modoki.
While traversing through worlds to find Sakura's feathers, the four travellers and Mokona are forced to overcome many dangers and opponents, some of whom are figures from Syaoran's past who wish to collect Sakura's feathers for their own reasons as they are seen to be objects that hold great power.
But the world is not so simple. The time they made a decision, their destinies were sealed into the tragic course, as everyone in the group has their own secrets...And they thought, that the masks would never fall...
The manga adopts darker and more complex tones in the latter half of the story. Because of the crossover characters with xxxHolic, the two manga occasionally intertwine with each other.'' -
https://tsubasa.fandom.com/wiki/Tsubasa:_RESERVoir_CHRoNiCLE#Story

