"Ryu... take care of Mebius and the Earth."
- ―Serizawa's last words
|Transformation Item||Knight Brace/Force of Will|
|Home world:||Earth (Nebula M78 Universe)|
|First Appearance:||Ultraman Mebius episode 1 "A Fateful Encounter" (As current captain of GUYS)|
|Last Appearances||Ultraman Mebius episode 35 Azure Waves of Light and Shadow (As former Captain of GUYS),|
Ultraman Mebius Gaiden: Armored Darkness (Voice Only)
|Type:||Anti-Hero, later Hero|
|Portrayed by||Shin Ishikawa|
Kazuya Serizawa (セリザワ・カズヤ Serizawa Kazuya?) is the first human host of Ultraman Hikari. Serizawa was originally thought dead until his reappearance under Hikari's control. He was the captain of GUYS Japan before his apparent death and Sakomizu replaced him. Originally it seemed his humanity was cut out by the vengeful Hikari but after the last battle with Bogal it was his will that allowed Mother to restore the ailing Ultra and restore his Ultra Spirit.
Serizawa was the former commander of GUYS. When Dino Zaur invaded the Earth, then-captain Serizawa had Ryu eject from their jet while he made a suicide run at Dino Zaur high above the earth. However, just before dying, Hunter Knight Tsurugi united with him. After destroying Dino Zaur Reverse, he was asked by Mirai to return, an offer which he refused and told Mirai to take care of Ryu in his absence as he left the Earth. In episode 35, he returns to Earth after an impostor attacks it in his form. He fights the impostor, the Alien Babalou, and after winning he returns to space. Hikari's power was inherited to Ryu in Episode 49.
Powers and abilities
- Super Speed: When fighting Bogal's human form Serizawa was able to move at superhuman speeds
- Strength: During his clash with Bogal, Serizawa showed enough strength to match the alien when they were pushing against each other
- Knight Brace Blade: Using the blade of the Knight Brace Serizawa can cut through ordinary materials with impunity and fire arcs of energy
- ESP: Serizawa can perceive events outside of his visual range
- Telepathy: His first spoken words in the series were with his mind
- Transformation: Serizawa can use the Knight Brace to transform into Ultraman Hikari
- Flash Travel: Serizawa can transform into a ball of light, when Hikari gave the Knight Brace to Mebius this was their method of transformation
During his time as Hikari's/Tsurugi's host, Serizawa transformed two ways, one was by using the Knight Brace and the other was using the Flash Travel ability to switch between forms. When using the Knight Brace as Tsurugi, his transformation scene was in front of a dark background and Tsurugi's rise was through a dark tunnel of crystal walls. As Hikari, his back ground was bright yellow and Hikari's rise was first a dark prismatic desging which changed to green/yellow color upon his growth.