If you're looking for manga similar to Crown (Tatsurou NAKANISHI), you might like these titles.
Junior high student Ken Ishii is good at nothing but getting out of trouble. An unidentified man appears before Ken as he is running away from hoodlums trying to pick a fight, like usual. The man asks "Do you know Zuieki Nogi?" and Ken shakes his head. Two onlookers observe them from a hiding place. The unidentified man unleashes a monster, catching Ken who is unable to get free. On the verge of death, something changes within Ken’s body…!? “Stand up as a ‘Shinobi’leader!” This is his destiny, to be shackled to a dying shinobi family’s fate...
Kairi is a boy who works with the OIL stand. One day, when Kairi finishes his work, he encounters a girl who had a big sword. She had to search for her older brother, who is the owner of the sword.
A girl named Tika, that has a great, mysterious, power is involved in the cruel battle for hegemony between 3 great kingdoms.
Hina and Nata lived as childhood friends born on the same birthday of the same year. However, after the entering to high school, Nata decided to leave the town and gradually became estranged from Hina because of that. One day two witches Sabbath and Pargo mysteriously landed on Earth. Hina protected Nata from one of Sabbath's attack and receives a fatal injury. The other witch, Pargo who saw that gives Hina and Nata a magical power at a cost of his body, and tells Nata to go on an adventure with Hina to regain his lost body. Thus, the adventurous journey of Hina and Nata began to regain what they lost and to stop the ambition of Sabbath..
The World Rift. A giant line of water jets that divides the world in two. Eight years ago, an epic battle punctured a hole through the rift and strange creatures began to leak into the known world, making it so that the only ones who venture out to sea are fools and pirates.Cherry Blossom is one of these aspiring pirates, setting out to sea in order to find something important to him. Along the way, he crosses paths with Sun, a mysterious boy who holds the World Rift Tear, an amulet said to be the key to traversing the World Rift and discovering what lies beyond. Together, they set out into uncharted seas, inviting any grand adventures that awaits them!
Coco is the naive girl and the granddaughter of a famous pirate, living on an isolated island. One day she saved a sword-cat, Bakado, who claimed to be the partner of her grandfather. Both of them have Garudia (enchanted jewels having magic power). Under Bakado's persuasion, they started off on a journey, hunting Garudia.