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Infinite Stratos Wiki
 Pilot Houki Shinonono
 Generation Type 4th Generation
 Battle Type Custom Close-Quarters Combat Type
 Armaments 2x foot-mounted beam blades

Twin Katanas ("Amatsuki" and "Karaware")

 Manufacturer Tabane Shinonono

Akatsubaki (紅椿, lit. Red Camellia?), is the first 4th-Gen personal IS, specially designed for Houki Shinonono by her older sister and IS creator Tabane Shinonono, built from the experiment data resulting from Byakushiki's modifications.


It is considered extremely rare, as the entire world is still experimenting with 3rd-Gen models. According to Tabane, Akatsubaki is currently the most powerful IS in terms of basic capability, since it is the first true 4th Generation IS and therefore Akatsubaki is equipped with fully functional Fold-Out Armor that double its normal stats. In a nutshell, this makes Akatsubaki an evolved version of the Yukihira Nigata. It is designed to be an all-rounder unit, and more importantly, a match to Ichika's Byakushiki. It has a larger energy shield supply than Byakushiki's. The unit boasts extreme acceleration that can outmanoeuvre multiple missiles and make quick turns in the air. 

Standby Form

It takes the form of a pair of gold and silver bells wrapped around Houki's left wrist by a red and black ribbon divided by a white line.

1st Shift/Armaments & Abilities

When in use Akatsubaki is a very angular unit with red armour and gold trim. When activated the unit can produce fold out armor which takes the form of multiple pink plasma glows on the rear wings and shoulders. The unit seems to have two pairs of wings unlike all of the other IS which only have their shoulder pauldrons. Also the unit does not have the large foot stabilizers shown on the other models. The blades Amatsuki and Karaware initially take the form of ordinary swords. However when the fold-out armour is activated their blades convert to pure energy and become able to send out shockwave attacks (Karaware) that can cut through objects, as shown when Tabane Shinono (Houki's older sister) produces a landbound missile launcher and fires several projectiles at Akatsubaki which get cut to ribbons, and a powerful red laser barrage (Amatsuki).


  • Foot Blade - A Blade generated through the foot for CQC
  • Twin Katanas (Close-Range) with individual abilities:
  1. Amatsuki (雨月, Rainy Moon?): The katana on her right which is optimized for 1 on 1 combat. With its secondary function activated, it shoots out multiple red-colored laser beams from around the IS, in a concentrated pattern toward a single target.
  2. Karaware (空裂, Cracked Sky?): The katana on her left which is optimized for combating multiple enemies. With its secondary function activated, it shoots out a large beam slash in the form of a crescent moon or in the shape of a wave at the target and can even take out multiple targets around it.
  3. 2 blade bits that detach from the wings of Akatsubaki for aerial combat after the activation of the Fold-Out Armor.
  4. Thousand Pierces (穿千, Ugachi?) Akatsubaki's new arsenal upon Volume 7, A Blaster Crossbow that was created after Houki 'gained experience values to a certain extent'. Fires a crimson red laser where the output is variable according to the pilot.

One Off Ability

  • Kenran Butō (絢爛舞踏, Gorgeous Dance?): - Enables Houki to recover the energy of Akatsubaki, and also recover energy to nearby IS's she comes in contact with. When activated, Akatsubaki realising a golden glow from his entire frame. It is presumed that Tabane specifically chose this ability so Houki could act as the primary support for Ichika's Byakushiki, which usually suffers from high energy consumption rate. Also, it acts as a pair with Reiraku Byakuya that is Byakushiki's ability to Destroy Energy. This gives Houki a major advantage over other IS's, as she can continually recover her energy as many times as possible.