Kaiju Keys (怪獣キー Kaijū Kī) are items that GUTS-Select use in conjuction with GUTS Sparklence to fire specialized ammunition. In the case of Ignis, using them allows Trigger Dark to harness their powers in his attacks and Circle Arms. When not in use, they are stored in the GUTS Buckle (
They also have Ultra counterparts called GUTS Hyper Keys.
Known Existing Hyper Keys
- Gomora Key
- Eleking Key
- Zetton Key
- Gamakugira Key
- Gazort Key
- Zaigorg Key
- Horoboros Key
- Nurse Key
- Gan-Q Key
- Gargorgon Key
- Golza Key
- As the Kaiju Keys are mostly sold in real life through SG and Gashapon releases, they lacked built-in electronics despite reusing the same plastic molds like the GUTS Hyper Keys (as the latter's battery compartment exists). Announcements on their characteristics were made through combination pins through the DX GUTS Sparklence, hence they have no special announcements when used in DX Circle Arms.
- The only exception to this are the Zaigorg and Horoboros Keys, as they are released alongside the Black Sparklence in Premium Bandai.
|Ultra Powers, Traits, and Objects of Interest|
|Powers and Traits||Ultraman Title | Ultra Beam | Ultra's Inner Light | Color Timer | Beam Lamp | Sluggers | Protectors | Ultra Horns | Bracers and Bracelets | Solar Energy Absorption | Forehead Crystal | Light Crystal | Body Crystals | Ultra Armor | Mental Abilities | Ultra Language | Human Hosts/Forms | Dimensional Field | Star Marks | Baradhi|
|Ultra-Related Items||Transformation Item | Spacium | Ultra Bell | Ultra Key | Ultra Mind | Plasma Spark | Ultlive | Childhood Radiation|
|Series Collectibles and Holders||Spark Dolls | Cyber Cards | Ultra Fusion Cards | Ultra Fusion Card Holder | Kaiju Cards | Ultra Capsules | Ultra Capsule Holder | Kaiju Capsules | R/B Crystals | R/B Crystal Holder | R/B Crystal Collection Case | Ultra Taiga Accessories | Ultra Access Cards | Ultra Medals | Z Holder | Kaiju Medals | GUTS Hyper Keys | Kaiju Keys|
|Other Media||Plasma Ore | Ultraman Suit | Ultraman Factor|