A defensive Trigger. It's more durable the smaller it is.

Osamu Mikumo about Shield, in Osamu Mikumo 5.[1]


Shield (18)

Ai Shield

Kanji シールド
Rōmaji Shīrudo
Organization BrDr Border
Type White trion Normal
Classification Defense Defense
- Mid to high defensive power
- Adjustable shape and size
- More durable when immobile
First Appearance
Manga Chapter 8
Anime Episode 4

Shield (シールド Shīrudo?) is the main Defense Trigger in Border. Its durability can be increased by activating Fixed Mode (固定(こてい)モード Kotei Mōdo?).[2]


Shield generates a smooth, transparent green barrier whose shape and size can be freely altered. When it is activated, a glowing green hexagon appears on the user's hand[3] or in correspondence of the body part it was cast from.[4][5][6] The majority of Border users summon hexagonal Shields, possibly suggesting that is the Trigger's default shape. The barrier also seems to have a default size, allowing it to protect the head and torso of a person of average height, as it leaves a fleeting, luminous impression of its original size when compressed.[7][8][9]


It is unknown when Border created this Trigger. Since some Neighbour countries use a similar Trigger,[10] it may be part of the technology that Border acquired in the Neighborhood.[11] Its performance rate has been increased over time.[12]


Tokieda support

Mitsuru Tokieda saves Jun Arashiyama.

Shield is considered an indispensable Trigger for all Border agents, regardless of their class and rank. It allows the user to conjure a barrier to defend against enemy attacks. Since it is capable of hovering, it leaves the user's hands free.[13] It can move along with the user[14][15] or remain fixed where it was cast.[16] It can generally be deployed anywhere within 25 meters of the user, although the distance oscillates according to the user's trion levels.[17] Shields can be cast remotely by one or more agents to protect an ally.[18] An immobile barrier will be more durable than a moving one.[19] A Shield which suffers more damage than it can withstand will crack and eventually break.[4]

Suwa shield

Kōtarō Suwa's focused Shield.

The durability of a barrier is inversely proportional to its surface area[1] and directly proportional to the user's trion levels.[20] With normal trion levels and bullet parameters, a Shield broad enough to protect the user's head and torso can withstand multiple rounds from a Gunner Trigger[21] as well as Lightning.[22] Conversely, it is necessary to erect a barrier measuring only a few inches across to block an Eaglet shot[23] or a thrust with Scorpion,[24] whereas a thrown, spinning one is capable of piercing it.[25] Kō Murakami, one of Border's top Attackers,[26] was able to crack one such focused Shield with a single swing of his Kogetsu, breaking through it moments later by continuing to apply pressure.[4] The process of shrinking a Shield appears to be virtually instantaneous,[7][8][9][27] and, aside from defensive purposes, it may be undergone to remove a barrier from the path of one's attack without dispelling it alogether.[28] Should the user be unwilling to reduce the surface area of their barrier, they can muster enough defensive power to defend against Eaglet by activating a second Shield,[29] provided they have enough chips in their Trigger Set; however, casting Shield through both the Main and the Sub, an act known as Full Guard,[30] prevents the user from fighting back, so caution still needs to be exercised.[31] Both Full Guard[32] and focused Shields[33] can be easily pierced with Ibis, unless the user boasts exceptionally high trion levels:[32] Hyuse[34] and Masataka Ninomiya[35] are capable of repelling it with Full Guard, while even one Shield cast by Chika Amatori can withstand the impact.[36]

Shield (Anchor Mode)

Ai Kitora activates Fixed Mode.

A Shield can not only be concentrated, but also fully shapeshifted,[13] even after it has already been cast,[37] or be divided into a myriad of small barriers.[38] Gunners can create an opening in their Shield to fire their weapon without exposing themselves,[39][40] its transparency allowing them not to lose sight of the enemy. Multiple agents may combine their morphed Shields to increase the retain a large surface area without sacrificing durability.[5] Spherical Shields allows the user to protect themselves against multidirectional[41] or explosive attacks[42][43] without sacrificing motility; alternatively, they may resort to Fixed Mode, which increases its durability in return for the inability to move it from its original position.[2] It is possible that, in order for this mode to be activated, the Shield must be given a prismatic shape, fully encasing the user, and/or rest on a solid surface at the moment of activation.[44][45]

Shield does not interfere with Triggers which lack direct destructive power, and is thus unable to block Lead Bullet.[3]


Shield is part of the Trigger set of every A and B-rank agent participating in Rank Wars,[46] as well as in Yūichi Jin's[47] and those of the members of Tamakoma First,[48] for a total of 94 known users, which makes it the most popular Trigger in Border. The total number of Shield chips, however, is a minimum of 183, as all but six official agents have two Shields in their Trigger set;[46] the exceptions are Kyōsuke Karasuma,[49] Osamu Mikumo[50][51] and the four Bagworm Tag users.[52][53][54][55] Masafumi Shinoda has also used this Trigger.[56]

The only confirmed users of Fixed Mode are Ai Kitora[2] and Chika Amatori.[45]


  • The first Shield used in the series[44] was in Fixed Mode.[2]
  • When Chika used her Shield in Fixed Mode, a piece of the roof she had been standing on prior to the activation of the Trigger was shown to be encased inside of the barrier.[45] It is unclear whether this means that Shield can phase through objects not made out of trion, that it automatically expands when obstacles are removed, or something else.
  • In Border, dummies can be fitted with Shields to help Shooters practice.[57]
  • "Shield" is also the name of one of the seals of Yūma Kuga's Black Trigger. The two are also similar in appearance and functions, and both are more durable when fixed in place.[58]
Galopoula Shield

Galopoula's shield Trigger.

  • Combatants from Galopoula possess a very similar Trigger, which is pentagonal and seemingly more durable than Border's version, since it was capable of blocking Fūjin's remote slashes. Users either have at least two such Triggers in their equipment, or are able to generate two barriers with the same one.[10]
  • Chelidon can generate circular barriers not dissimilar to Border's Shield, whose number and diameter can be increased or decreased at will.[59][60]
  • Rodochroun, a planet-nation that specializes in the making of Trion Warriors, is able to manufacture models that can generate shields, such as Manberdo Dogs[61] and Idras. The latter are particularly remarkable for their ability to combine their shields to increase their durability,[62] but even the shield of a single Idra can withstand a Kogetsu slash without cracking.[63]


  1. 1.0 1.1 World Trigger Manga Chapter 36 (p. 10)
  2. 2.0 2.1 2.2 2.3 Daisuke Ashihara: Q136: The Shield Kitora used in Chapter 8 to surround herself, was that a normal Shield? A: It was a normal Shield that she used in "Fixed mode". It cannot be moved from where it sprouts from, but in return the durability is enhanced.
    Source: Border Briefing File, Question 136
  3. 3.0 3.1 World Trigger Manga Chapter 29 (p. 6)
  4. 4.0 4.1 4.2 World Trigger Manga Chapter 99 (p. 6)
  5. 5.0 5.1 World Trigger Manga Chapter 100 (p. 7)
  6. World Trigger Manga Chapter 139 (p. 10)
  7. 7.0 7.1 World Trigger Manga Chapter 89 (p. 16)
  8. 8.0 8.1 World Trigger Manga Chapter 134 (p. 6)
  9. 9.0 9.1 World Trigger Manga Chapter 189 (p. 8)
  10. 10.0 10.1 World Trigger Manga Chapter 125 (p. 8)
  11. World Trigger Manga Chapter 134 (p. 9)
  12. World Trigger Manga Chapter 107 (p. 8)
  13. 13.0 13.1 World Trigger MangaBorder Briefing File (p. 220)
  14. World Trigger Manga Chapter 155 (p. 8-9)
  15. World Trigger Manga Chapter 156 (p. 1)
  16. World Trigger Manga Chapter 186 (p. 14)
  17. Daisuke Ashihara: Q: How far can an agent deploy a remote Shield like the ones used in the battle with Lamvanein? A: It depends on individual ability, but they should be able to deploy a Shield up to 25 meters away. This remote defense is one of the reasons that Shield is superior to the shield on the Raygust.
    Source: Question Corner 8, Volume 9
  18. World Trigger Manga Chapter 60 (p. 17)
  19. Daisuke Ashihara: Q: What is the difference between Shield, Raygust (shield version), and Escudo? A: Shield: Can change shape. Durability changes according to the size of the surface area. Moving it lowers the durability. Raygust: Can change shape. Durability changes a little according to the size of the surface area. Even if you wave it around in your hand the durability will not change. Escudo: Cannot change shape. Cannot be moved. High durability. Needs a place (such as a wall or floor) to grow out of.
    Source: Question Corner 11, Volume 18
  20. World Trigger Manga Chapter 113 (p. 11)
  21. World Trigger Manga Chapter 168 (p. 7-8)
  22. Daisuke Ashihara: Higher muzzle velocity means it's easier to hit a target, but less power means Shields can block it.
    Source: Sniper Triggers, Volume 4
  23. World Trigger Manga Chapter 89 (p. 6-7)
  24. World Trigger Manga Chapter 114 (p. 7)
  25. World Trigger Manga Chapter 194 (p. 3)
  26. World Trigger Manga Chapter 49 (p. 4)
  27. World Trigger Manga Chapter 190 (p. 13)
  28. World Trigger Manga Chapter 189 (p. 11-12)
  29. World Trigger Manga Chapter 186 (p. 9)
  30. World Trigger Manga Chapter 26 (p. 16-17)
  31. World Trigger Manga Chapter 182 (p. 10)
  32. 32.0 32.1 World Trigger MangaBorder Briefing File (p. 105)
  33. World Trigger Manga Chapter 113 (p. 14-15)
  34. World Trigger Manga Chapter 186 (p. 12)
  35. World Trigger Manga Chapter 114 (p. 14)
  36. World Trigger Manga Chapter 187 (p. 10)
  37. World Trigger Manga Chapter 112 (p. 10)
  38. World Trigger Manga Chapter 76 (p. 7)
  39. World Trigger Manga Chapter 112 (p. 1)
  40. World Trigger Manga Chapter 139 (p. 5)
  41. World Trigger Manga Chapter 191 (p. 15)
  42. World Trigger Manga Chapter 192 (p. 6)
  43. World Trigger Manga Chapter 194 (p. 4)
  44. 44.0 44.1 World Trigger Manga Chapter 8 (p. 16)
  45. 45.0 45.1 45.2 World Trigger Manga Chapter 187 (p. 22)
  46. 46.0 46.1 World Trigger MangaBorder Briefing File
  47. World Trigger MangaBorder Briefing File (p. 99)
  48. World Trigger MangaBorder Briefing File (p. 91-95)
  49. World Trigger MangaBorder Briefing File (p. 95)
  50. World Trigger Manga Chapter 164 (p. 14)
  51. World Trigger MangaBorder Briefing File (p. 141)
  52. World Trigger MangaBorder Briefing File (p. 45)
  53. World Trigger MangaBorder Briefing File (p. 74)
  54. World Trigger MangaBorder Briefing File (p. 86)
  55. World Trigger MangaBorder Briefing File (p. 183)
  56. World Trigger Manga Chapter 71 (p. 13)
  57. World Trigger Manga Chapter 109 (p. 15)
  58. World Trigger Manga Chapter 15 (p. 19)
  59. World Trigger Manga Chapter 54 (p. 16)
  60. World Trigger Manga Chapter 59 (p. 11)
  61. World Trigger Manga Chapter 130 (p. 4)
  62. World Trigger Manga Chapter 124 (p. 10)
  63. World Trigger Manga Chapter 129 (p. 10)


e - d - vBorder Triggers
Basic Equipment Bail OutRadarTrion Body
Attacker Kogetsu (Kogetsu: Spear) • Raygust (Shield Mode) • ScorpionSōgetsu (Axe)
Gunner Asteroid • Cobra • Gimlet • Hornet • HoundMeteorSalamanderTomahawkViper
Firearms Assault Rifle • Grenade Launcher • Handgun • Minigun • Shotgun
Sniper EagletIbisLightning
Defense EscudoShield (Affixed Mode/Full Guard)
Trap Switchbox
Optional Bagworm • Bagworm Tag • ChameleonConnector • Dummy Beacon • Enhanced Radar • Full ArmsGeistGen'yōGrasshopperIdatenLead Bullet • Makō • Senkū • Silencer • SpiderStarmakerTeleporterThruster • Timer
Prototypes Connector • Dummy Beacon • Full ArmsGeistIdaten • Makō • Teleporter • Timer
Black Fūjin • Tsukihiko Amō's Black Trigger • Yūma Kuga's Black Trigger
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