Isabelle (イザベル Izaberu) is a vessel from Government.[1] She was known as Sayuri Kawamo (川面サユリ) prior to forcefully becoming a vessel.


Isabelle is a short, white-skinned, small-chested girl with bright blonde hair cut short and blue eyes. She wears a red hat and an identically-colored military uniform with a tight skirt. The black belts placed all over the uniform allow it to double as a straitjacket. On her feet, she wears knee-high boots which also have belts wrapped around them.[1] Her blonde hair and blue eyes are a result of her being artificially given the talent to be a vessel. When she was Sayuri Kawamo she had long black hair.[2]


At first glance, Isabelle acts emotionless and always talks with a deadpan voice, being very focused on fulfilling her job as a vessel. Despite her lack of outward emotions, Isabelle has some strange quirks, such as her request for a suitable reward, which is often food like family restaurant's menus or desserts, before doing a job/task and her refusal to follow further orders until said reward is given to her. She also has the habit to classify things, including her own feelings, by their size; saying things like "small-sized", "mid-sized" or "super-sized".[3] While she lacks any memories of her previous life before becoming a vessel, Isabelle still feels a bond towards Kuina Murasame, and asked Kyousuke Shiroyama to save her.[4]

As a child, Sayuri was incredibly close to Kuina, with both of them being close friends who shared everything. According to Kuina, Sayuri was a worrier and a crybaby that seemed quiet and plain, but was actually a jack-of-all-trades who could do anything, though she herself didn't notice this about herself. She also was a fan of collecting mascots such as Juddark and Sherif Kitty,[5] a trait that seems to persist in Isabelle.


Sayuri had been close friends with Kuina Murasame since they had been little and they lived in Harukawa City. However, Sayuri was kidnapped by Government and used in their Anthill Project, becoming a vessel and losing her former identity.[5]

She and Kyousuke had met a bit before their contract during the mid-air battle with Illegal. During their meeting Kyousuke had revealed to her that Kuina Murasame would be involved in his next mission. Isabelle then made a contract with Kyousuke to help save Kuina.[4]


Light Novel Volume 03Edit

Isabelle was aboard the same convoy carrying Maria Heartocean. When they were attacked by Illegal forces she made a contract with Kyousuke Shiroyama, and the two defeated all enemy forces.[1] The two then arrived at Toy Dream 35, and Isabelle entered Kyousuke's home the following day and woke him up to demand her reward for the fight.[3] After eating at the family restaurant Kyousuke asked Isabelle to kill some time until school ended.[6] She and Kyousuke ambushed the new transfer student, Youji Makihara, and took away his Girl's Backdoor.[7] The two later discussed their next move during lunch, deducing there would be more people with Girl's Backdoor in the city and deciding it would be best to move against them before they did anything.[8]

Some time later Kyousuke and Isabelle finished hunting down the other users of Girl's Backdoor. The two were informed of a Material battle being started at A Block.[9] Since Kyousuke lacked enough information on their enemy and their goals he and Isabelle paid a visit to Lu Niang Lan in C Block. While they talked Lu informed them of the destruction of a Government base in D Block and they concluded that the enemy had to be a Freedom summoner. Lu suggested they ask Aika about Anthills.[10] Isabelle and Kyousuke went to her apartment, as she refused to talk about it on the phone. Once there Aika revealed to them that the Anthills were a secret Government project to artificially create vessels for their faction.[11] Lu suddenly arrived at the apartment and attacked them, as she was under the influence of Girl's Backdoor. She quickly knocked out Isabelle, Aika and Aika's liger, but Kyousuke managed to set off a trap using the sprinklers and the wiring to knock all of them out.[12] However, upon waking up they realized Aika had been controlled through Lu to leak the list of Anthills to the enemy.[13] As the group tried to decide in a course of action Aika was suddenly called by a Government coordinator, who wished to discuss her security leak, informing them that the superiors were very angry and were blaming her and her Illegal acquaintance, as they had never liked the apartment were agents of the three world powers gathered in peace. Kyousuke was told that he would had to help Government free of charge with their Anthill evacuation. Kyousuke pointed out the flaws on their plan, and offered to help her convince her superiors to change it.[14]

After Kyousuke proposed his plan to Government he parted ways with Isabelle to meet with Biondetta Shiroyama.[15] Meanwhile, Isabelle met with Kuina Murasame, who explained to Isabelle what Government had done to her and asked her to stand down, as she didn't want to fight her. Isabelle refused to comply with her request.[2] A fight eventually broke out between the two pairs, and Biondetta's tricks allowed her to cause a chain reaction with the Petals and reach the Divine-class while Kyousuke was still in the Regulation-class, giving her the advantage. However, Kyousuke pointed out that she had wasted a lot of time setting up her strategy, and ordered Isabelle to destroy their footing to waste the remaining time of the ceremony and escape.[16] As they retreated they were contacted by Government, who informed them that the preparations for the evacuation were being finished. The two confirmed their desire to save Kuina from Biondetta.[17]

Biondetta and Kuina easily defeated the Pilot Soldiers protecting Government's VIP, Maria Heartocean, after Biondetta tricked the officer in charge of the evacuation.[18] Before they could kill her they were suddenly interrupted by Kyousuke and Isabelle's arrival. Isabelle and Kyousuke revealed to Kuina that Biondetta had manipulated her with Girl's Backdoor and that they had been trying to help her from the beginning. Biondetta used the Girl's Backdoor she had hidden inside her left arm to control Kuina and force her to fight Isabelle, intending to make her destroy her own friend to break Kuina and extend the target of her revenge to the rest of the world.[19] Biondetta engaged them in a fight, with her tactics once again giving her the upper hand, but Kyousuke managed to take away her domino setup with the support of the pilots of the Stingray, reaching the Divine-class. On Kyousuke's order, Isabelle attacked and defeated Biondetta and Kuina.[20][21]

The following day Isabelle agreed to meet with Kyousuke on a park. However, Kyousuke didn't meet with her in person, instead choosing to call her by phone. He explained that Kuina would be fine, as he had forced Biondetta to cancel her contract with her. However, this would erase all of Kuina's memories of Sayuri/Isabelle, so Kyousuke decided to finish his contract with Isabelle, making her a normal person again. Isabelle complained that this would also erase her memories of him, but Kyousuke brushed away her complaints, stating her request to save Kuina Murasame wouldn't be completely fulfilled without returning her friend to her. Kyousuke appeared from within the nearby crowd and canceled the contract. Isabelle forgot about Kyousuke, and was reunited with Kuina, who now believed Isabelle's new name and image to be some sort of image change.[22]

Light Novel Volume 09 Edit


Despite originally being a completely normal person, Isabelle has had the talent to be a vessel implanted in her through the Anthill Project.[2] Isabelle's restraints are the multiple belts on her clothes.[1]


  1. 1.0 1.1 1.2 1.3 Mitou Shoukan://Blood Sign Volume 03 Opening X-02
  2. 2.0 2.1 2.2 Mitou Shoukan://Blood Sign Volume 03 Stage 3 Part 5
  3. 3.0 3.1 Mitou Shoukan://Blood Sign Volume 03 Stage 1 Part 1
  4. 4.0 4.1 Mitou Shoukan://Blood Sign Volume 03 Stage 3 Part 6
  5. 5.0 5.1 Mitou Shoukan://Blood Sign Volume 03 Stage 3 Or a Story Set Further in the Past
  6. Mitou Shoukan://Blood Sign Volume 03 Stage 1 Part 2
  7. Mitou Shoukan://Blood Sign Volume 03 Stage 1 Or a Story Set Somewhat in the Past
  8. Mitou Shoukan://Blood Sign Volume 03 Stage 1 Part 4
  9. Mitou Shoukan://Blood Sign Volume 03 Stage 2 Part 2
  10. Mitou Shoukan://Blood Sign Volume 03 Stage 2 Part 4
  11. Mitou Shoukan://Blood Sign Volume 03 Stage 2 Part 5
  12. Mitou Shoukan://Blood Sign Volume 03 Stage 2 Part 7
  13. Mitou Shoukan://Blood Sign Volume 03 Stage 2 Part 8
  14. Mitou Shoukan://Blood Sign Volume 03 Stage 3 Part 1
  15. Mitou Shoukan://Blood Sign Volume 03 Stage 3 Part 4
  16. Mitou Shoukan://Blood Sign Volume 03 Stage 3 Part 7
  17. Mitou Shoukan://Blood Sign Volume 03 Stage 3 Part 9
  18. Mitou Shoukan://Blood Sign Volume 03 Stage 4 Part 2
  19. Mitou Shoukan://Blood Sign Volume 03 Stage 4 Part 3
  20. Mitou Shoukan://Blood Sign Volume 03 Stage 4 Part 5
  21. Mitou Shoukan://Blood Sign Volume 03 Stage 4 Part 6
  22. Mitou Shoukan://Blood Sign Volume 03 Ending X-01