五河 士道 (Itsuka Shidō)
The protagonist of Date A Live. Shido is a kind-hearted and sympathetic young man who possesses a strange power that allows him to seal the powers of a Spirit in his body with a kiss; however, the seal will only work if the Spirit holds enough trust or affection toward him to allow it. This ability allows him to seal and contain 99% of a Spirit's power. After sealing a Spirit's powers, there will be an invisible link connecting him and the Spirit, through which a portion of the sealed power will flow back to the Spirit if said Spirit's mental state becomes unstable, and back to Shido once the Spirit's mental state stabilizes. In volume 5, he discovers he can access the powers of the Spirits, including Tohka's Sandalphon, other than Kotori's healing flames that he has sealed. While Shido usually maintains a close bond with each of the Spirits he saves throughout the course of the series due to promises he has made, he is most often shown to be particularly close to Tohka.
After sealing the power of multiple Spirits, Shido's own power goes unstable in Volume 12, changing his personality and turning him into a threat. To restore Shido's normal self, Kotori and the other Spirits must come together to kiss him, so as to calm down his unbalanced sealed power, which will cause a disaster worse than what had happened 30 years ago. While having a completely different personality, Shido is conceited, displaying a dark demeanor and tends to 'impress' familiar people, by showcasing the powers of the Spirits he had sealed (In this case, the power belonging to Yoshino, Miku, Natsumi and Origami). Near the end of volume 12, during his date with Yoshino, DEM interfered and tried to capture Shido, but he destroyed the team of 20 Bandersnatch easily using a powerful spirit flash. Later, Shido's sealed powers went completely berserk during his date with Tohka due to the Second Spirit's noise calling out for him. Fortunately, Shido was saved by Phantom, who then weakened Shido's spirit barrier, so the Spirits can successfully break through to kiss him.
Assumed to have been abandoned by his birth mother, Shido lives with his foster sister Kotori. He has blue hair and brown eyes, and is in his second year in Raizen High School, class 2-4. He was in despair for a time after being abandoned and subsequently adopted, which made him sensitive to similar feelings from others and wanting to bring them out of it, fueling his desire to save the Spirits. He meets his real sister Mana Takamiya later in volume 3. In volume 7, Westcott briefly addresses him as Takamiya before switching back to Itsuka.
Volume 17 reveals more details about his origin: born Shinji Takamiya, he actually lived around the time the first spatial quake hit and met the First Spirit, a nameless entity in the form of a girl, whom he called Mio. Over time, Shinji taught her about the world and life and the two fell in love with each other; until Wescott attempted to capture Mio and killed Shinji in the process. In an attempt to bring him back to life, Mio absorbed Shinji's corpse into her body and recreated him as a human/Spirit hybrid, explaining Shido's ability to seal and manifest Spirit powers. As it turns out, Mio has been distributing Sephira crystals among humans to perfect and refine their powers so that, in time, Shido can obtain them and become a being of unlimited magical power like herself so they can be together for all eternity.