Kaito Kiriya

A quiet and shy student who receives a message from an elven woman from End Earth. When he tells his friends, the group dismisses the message as they believe it to only be a dream. Kiriya is a skilled swordsman; ranging from kendo to fencing. It is said that no one could beat him if he was to fight seriously. The cherry blossom of their college transports him and Seena to End Earth right after Souma and Kureha, taking the entire building as well. He becomes the knight for an independent mercenary group called the 'Luminous Knights', which is started by Seena.

Like Souma, Kiriya is also a Soul Blader, who uses Seena's "heart" as a sword. Kiriya is completely oblivious to Kureha's and Seena's feelings for him, the latter being one of his childhood friends. He later forms a close bond with an elf named Xecty, who is later revealed to be an artificial recreation of the Elven Queen. Until Xecty's death, he was confident in his mission to have Saionji admit defeat. Since the start of the war, his attitude shifted from his shy and quiet self, to a rash and emotional state, who sees that fighting is the only way to win (the complete opposite to Souma's change of behavior).

He is later revealed to hold Souma's Holy Grail, Souma's Ultimate Soul Blade (究極心剣, Kyūkyoku Shinken?). The one who holds his Holy Grail is Xecty.

In the end, he chooses to return to his own world, together with Kureha and Seena.

(source: Wikipedia)