"It's spread throughout the universe, circulating within planets and lifeforms. In order to gather this energy, the man created a certain material. He names this material the Carellen element. But its only stabilize within the bodies of living creatures. The man disperses the Carellen element about, which lets him use living things to cultivate high-density energy. This energy, which tends to circulate planets and lifeforms, is known as Childhood Radiation."
- ―Kei Fukuide, The Geed Identity.
Childhood Radiation (幼年期放射 Yōnen-ki Hōsha) is an energy/essence which first appeared in Ultraman Geed.
The Childhood Radiation is in fact a raw form of energy which can only be cultivated within life forms. Once cultivated within a life form, they would form an energy sphere called a Little Star (リトルスター Ritoru Sutā) and their host would experience symptoms such as feverish hands, light radiation from their chest and development of powers (which strangely corresponds to an existing Ultra Warrior). This also puts them at risk since most Kaiju are capable of tracking their Little Stars and are attracted in a similar manner like moths to a flame. Among the ways to separate them are through wishes upon an Ultra Warrior and strong emotions.
Carellen Element, a material which Kei developed, served as a magnet to Childhood Radiation and is a major key in the development of Little Stars. The Childhood Radiation plays a crucial part in the activation of Ultra Capsules. Once entering an empty Ultra Capsule, an image of its corresponding Ultra Warrior would appear.
Having stolen the Ultra Capsules in the Land of Light, Kei Fukuide realized that the activation of these devices required the Childhood Radiation. Kei created the Carellen Element as a magnet for the energy essence and had them cultivated within Earth life forms. Little did he knew is that Laiha Toba developed this symptom earlier than anyone else as she was saved by Ultraman King before her birth.
The first attempt to harvest Little Star began six years before the start of the series as Skull Gomora rampaged in the Mt. Mitsuse region and provoked Laiha by killing her parents. However, it caused the opposite outcome as her Little Star was suppressed by her grief and Kei simply walked off, unintentionally exposing himself.
The rest of the Little Star symptoms started to appear by the present day. Kei instigated a chain of events that would led the clone of Ultraman Belial, Riku Asakura to take up the mantle of Ultraman Geed and portray the role of hero. As Geed becomes the image of a hero, Kei watched from afar as future monster attacks (either by his own or other circumstances) would help the Ultra in collecting Little Stars as Ultra Capsules.
As of episode 16, AIB decided to take the Little Star cases into their matters, such as developing enzymes that would dissolve the Carellen Element and safely removing the Little Stars. They also quarantine patients in a building that block its signal from being detected by monsters.In episode 24, Belial Atrocious uses Kei's Sturm Organ (which he tore out from Kei's body earlier on) in his body to use the Carallen Element in the said organ to absorb the Childhood Radiation that circulated around space and converting it into evil energy to empower himself and disrupting the peace in the universe. However in the finale, after Zero delivered the Carallen Element neutralization enzyme into Belial's body, Belial would release King's Childhood Radiation and rendering the Sturm Organ ineffective.
List of Little Star hosts
|Host||Power||Ultra and symbolism|
|Laiha Toba (鳥羽 来葉 Toba Raiha)||Supernatural Hearing||Ultraman King's omniscience.|
|Eri Hara (原 エリ Hara Eri)||Pyrokinesis||Ultraman Leo's burning fighting spirit.|
|Toru Honda (本田 トオル Honda Tōru)||Armor of Light||Ultraseven's super resilience.|
|Alien Pitt Tri-Tip||Energy sword||Ultraman Hikari's status as a swordsman.|
|Moko||Healing||Ultraman Cosmos' power to soothe.|
|Mayu Igaguri (伊賀栗 マユ Igaguri Mayu)||Teleportation||Ultraman Zero's power to travel through space-time.|
|Sui Asakura (朝倉 錘 Asakura Sui)||Clairvoyance||Father of Ultra's ability to see anything.|
|Toko Sakura (佐倉藤子 Sakura Tōko)||Energy blade projection||Ultraman Jack's Ultra Bracelet.|
|Fujio Maga (満賀富士夫 Maga Fujio)||Energy slicer||Ultraman Ace's Vertical Guillotine.|
|Tetsuro Matsumoto (松本鉄朗 Matsumoto Tetsurō)||Mental Combustion||Ultraman Taro's Ultra Dynamite.|
|Gubila||Paralysing Spray||Zoffy's Z-Ray.|
- The Childhood Radiation is a reference to name of Arthur C. Clarke's novel, Childhood's End, which was used by series writer Otsuichi as a reference material. Meanwhile, Carellen Element, the material used to attract Little Star is a tribute to Karellen, an Overlord and the "Supervisor for Earth", the character from said novel.
|Ultra Powers, Traits and Objects of Interest|
|Traits and abilities||Ultraman Title | Ultra Beam | Ultra's Inner Light | Color Timer | Beam Lamp | Crest Weapons | Protectors | Ultra Horns | Bracers | Solar Energy Absorption | Forehead Crystal | Light Crystal | Zenshin Crystals | V Crystals | Ultra Armor | Mental Abilities | Ultra Signs | Human Hosts/Forms | Dimensional Field | Star Marks|
|Ultra-related Items||Transformation Items | Specium | Ultra Bracelet | Ultra Array | Ultra Bell | Ultra Key | Max Galaxy | Plasma Spark | Aarb Gear | Techtor Gear | Ultimate Aegis | Spark Dolls | Strium Brace | Ultra Fusion Brace | Knight Timbre | Cyber Cards | MonsArmor | Ultra Fusion Cards | Ultra Fusion Card Holder | Kaiju Cards | Ultra Capsules | Ultra Capsule Holder | Kaiju Capsules | Childhood Radiation | R/B Crystals | R/B Crystal Holder | R/B Crystal Collection Case | Ultra Taiga Accessories|
|Manga Only||Plasma Ore | Ultraman suit | Ultraman Factor|