Hikari Kaizaki (ヒカリ・カイザキDiaclone VS. Gridman. A young Dia-Nauts (ダイアクロン隊員 Daiakuron taiin Diaclone officer), Kaizaki is a chief researcher who bonded to the Hyper Agent Gridman as his host in the fight against Giganter.) is the main protagonist of the web-novel crossover
Hikari Kaizaki is designed by Masaru Sakamoto, who is also responsible for designing the human characters of SSSS.GRIDMAN. Hikari's Dia-Tector was intended to be flashy so as to appear standing out compared to other Dia-Nauts. In addition to the default color pink, Masaru also provided two other alternative colors; the first one was in a state when Hikari piloted the Grid Suit and other one was when she performed Access Flash with Gridman. He also added that her Dia-Tector was designed to resemble a toy. As seen in the concept art below:
- The first blue/neon green coloring is a stylish version.
- The other one is inspired by the Compoid race.
Pre-Diaclone VS. Gridman
Hikari used to live with her younger brother and were caught in the intense war between Earth and the Waruder Army. The two envisioned a hero of their own, named Silver Kration (シルバークラティオン Shirubā Kuration), with Hikari creating a representative doll in hopes that a hero would save them from the war. The doll also incorporated a green quartz taken from one of Jupiter's moons, Europa, by their father. Unfortunately Hikari's younger brother was killed at some point in the past. She became disillusioned with the concept of heroes, but swore to become one in order to prevent others from suffering the same fate as she did.
Although the fight against the Waruders had long ended, Hikari joined the Diaclone Team and rose to the position of chief researcher at the Moon's Diaclone Scientific Research Station.
Diaclone VS. Gridman
Hikari researched the combat artificial intelligence known as the BIG-AI as a way to synchronize Diaclone pilots to their mechas. After suffering from an injury when Gridman accidentally crashed her research lab, Hikari was visited by the Hyper Agent in her Dia-Tector's cyberspace, who asked for her cooperation in the fight against Giganter.
Hikari raced to Earth and at first defended a group of soldiers from Dimensional Parasite Monsters with the Grid Suit, a Powered Suit assimilated with Gridman. They then searched for Landmaster, the local governing super computer, in order to obtain his help. While Gridman spoke directly to Landmaster in Cyberspace, the three devised a means to use Gridman's powers to defeat the Waruder monster attacking Earth. This plan involved creating a assist machine to channel his natural dimension spanning powers, but to synthesize such a weapon required a special quartz found on Europa. While Gridman recharged his energy, Hikari gave them her quartz necklace to be used as the core of Thunder Crash Caliber.
Hikari merged with Gridman where her mental image of her ideal hero Silver Kration manifested into Gridman's Primal Fighter form. After the fight with Giganter, Hikari and Gridman bid farewell to wach others. At some point later, her experience when synchronized with Gridman was used as the final component for BIG-AI's construction, now affirming that anyone could be a hero.
- Age: 18 years
- Powers and Weapons
- Genius-Level Intellect: At a young age, Hikari accomplished the feat of being a young genius who excelled in the study of technology. Her research prior to Gridman's arrival was the creation of an artificial intelligence.
- Combat Proficiency: Like all Dia-Nauts, Hikari is a trained fighter.
- Piloting: Hikari has the knowledge of piloting Diaclone mechas, such as the Dia Wing and the Powered Armor.
- Acceptor (アクセプター Akuseputā): The transformation device which allows her to fuse with Gridman. It was upgraded into the Primal Acceptor in order to transform Gridman into Primal Fighter.
- Dia-Tector (ダイアテクター Daia Tekutā): A standard combat uniform utilized by the Diaclone officers in the combat field, it also acts as a pilot uniform in their mechas. Hikari's uniform is colored pink and specially used for diving into cyberspace, which is also inhabited by Gridman during his recuperation.
- Glowing Green Crystal (緑色に発光する水晶 Midori-iro ni Hakkō Suru Suishō): A space gem/quartz found at a crater on Europa, Hikari had one as a gift from her father and kept as memento of her late younger brother. The shard that she kept was used was replicated as the core of Gridman's Thunder Crash Caliber.
Diaclone VS. Gridman
- Assuming that she is responsible for Gridman's Primal Fighter form, this means that she is also indirectly responsible for the formation of Gridknight, whose appearance was adopted from Gridman as a result of copying the former's capabilities.
- Her Dia-Tector's color scheme is similar to Unison's uniform, but Masaru Sakamoto added that it was purely a coincidence on his part.
- According to Motoki Takaya, Hikari is the first Dia-Nauts to appear with a personal name.