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Related to Hijo, Virtuosity
Type Investiture
World Komashi
Universe Cosmere
Featured In Yumi and the Nightmare Painter
This page or section contains spoilers for Yumi and the Nightmare Painter!
This information has the ability to potentially ruin elements of the plot for the reader. Proceed with caution if you have not read this book.

Hion is a form of Investiture supplied by the hijo on Komashi, used to power technology on that world.[1] It typically takes the form of a pair of energy bands, colored light blue and magenta, called hion lines.[2]

Appearance and Mechanics[edit]

Hion lines can be found in a variety of sizes, ranging from wire-thin to at least the thickness of a wrist.[2] They originate from the ground, where they are called "hion stubs",[3] but from there hion lines extend into the air, branching out, and hang unsupported. Their coloring can be described in many ways, but in general they are said to be electric, energetic shades of cyan and magenta. They hum very quietly, and are motionless.[2] Touching a hion line gives an overwhelming, electrifying sensation.[4]

Hion lines are responsible for pushing back the shroud on Komashi, and consequently are pervasive in cities when the shroud was present. Primary lines a few inches across run down all major streets, floating about twenty feet above the ground, with thin branches winding down smaller streets and in poorer sections of town.[5] The lines themselves can be cultivated and extended, allowing for--among other things--cities to expand into the shroud or passageways between cities to be formed.[2][6] They are sometimes manipulated for more mundane reasons, such as using the lines themselves to create signage for streets and businesses,[2] or for more practical needs, such as bringing a power source into homes or supporting plant growth on farms.[5]

Hion is powered by the spirits, or hijo, on Komashi. For much of Komashi's history, this is directed by the father machine, though hijo are capable of supplying hion directly and of their own will.[1]


In Nagadan, hion lines are regularly used to support their technology. The simplest use is to create electrical power by connecting two hion lines together: a piece of metal placed between two lines will heat up, acting as a resistor.[7] This is commonly used for heating,[8] and can easily be exploited for lighting as well, among other possible applications.[7] Telephones can also utilize hion lines to send signals, though these can be very expensive.[9]

Hion viewers are a form of television that manipulates hion lines to produce images.[10] The lines themselves are placed behind a glass surface to prevent unwanted contact, and a knob is used to control the device.[10] These are made up of single continuous lines, one of each color of hion, which bend and twist in order to recreate images. These lines are thin enough that they are able to reproduce details as fine as eyelashes.[11]

One very common application of hion is in various means of transportation. Trains,[5] buses,[12] trolleys,[9] and boats[13] all make use of hion lines. In addition to everyday transportation methods, hion lines can also be used to power spaceships. The space bus engineered by Nagadan utilizes a mobile hion line which can be extended rapidly in the direction of desired travel.[13] From Komashi, this ship is capable of reaching at least as far as UTol and the Iron Seven Waystation.[13][1]

The characters of Seasons of Regret reference a hion blade, though this device may be fictitious.[11]


Scholars from the Institute of Mechanical Solutions first discovered the concept of hion and built a machine that could utilize the hijo to provide power to Torio. Despite the catastrophic, unforeseen consequences that followed the machine's activation, the device did fulfill its original purpose of providing hion. It generated hion stubs, emerging from the ground around the kingdom of Torio.[3] These began as bright lights emerging from the ground,[14] and were the only places plants could grow within the shroud.[14] Humans settled at these locations and learned to cultivate the hion lines, extending them and branching them out.[6] Due to the way hion was able to repel the shroud, these hion lines ultimately became the foundational aspect of infrastructure on Komashi, and in the seventeen centuries that followed they developed hion technology extensively.[14][15]

Hijo continued to supply the hion lines after the machine was destroyed, albeit willingly and in exchange for hion viewer dramas.[1]


  • The hion colors were intentionally picked as two of the colors commonly used in printers. It is as of yet unknown what happened to the color yellow.[16]
  • The two colors are a manifestation of the general Push-Pull theme that can be seen with all Investiture. It is, however, much more pronounced with Virtuosity.[17]


  1. a b c d Yumi and the Nightmare Painter Another Epilogue#
  2. a b c d e Yumi and the Nightmare Painter chapter 1#
  3. a b Yumi and the Nightmare Painter chapter 39#
  4. Yumi and the Nightmare Painter chapter 9#
  5. a b c Yumi and the Nightmare Painter chapter 3#
  6. a b Yumi and the Nightmare Painter chapter 21#
  7. a b Yumi and the Nightmare Painter chapter 5#
  8. Yumi and the Nightmare Painter chapter 19#
  9. a b Yumi and the Nightmare Painter chapter 14#
  10. a b Yumi and the Nightmare Painter chapter 11#
  11. a b Yumi and the Nightmare Painter chapter 25#
  12. Yumi and the Nightmare Painter chapter 7#
  13. a b c Yumi and the Nightmare Painter chapter 30#
  14. a b c Yumi and the Nightmare Painter chapter 24#
  15. Yumi and the Nightmare Painter chapter 32#
  16. Secret Project #3 Reveal and Livestream
    Arcanum - 2022-03-22#
  17. Shardcast Interview
    Arcanum - 2023-07-30#
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This page contains most of the knowledge we have on the subject at this time.
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