Umeko Tanaka
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Umeko blush

Umeko tanaka

Rōmaji Tanaka Umeko
Other Names System
Umeko-chan by Hitomi Saitō
Personal Information
Gender Female
Age 5-6
Status Deceased
Eye Red
Hair Dark Purple
Affiliation Fallen Black
Anime debut Episode 8

Umeko Tanaka (田中 運命子, Tanaka Umeko), also known as System (システム, Shisutemu), is a supporting character in Inō Battle wa Nichijō-kei no Naka de. She later became a member of Hajime Kiryū's clique. Her ability called White Rulebook, allows her to use any power the situation calls for.


When she first was introduced, she was seen having red eyes and long messy, dark purple hair and she was seen wearing a light green crop top and and short light green trousers.

However, after joining Fallen Black, Aki Natsu gave her new clothes and changed her hairstyle. She now has short, light purple hair and she always wear a big dark blue ribbon to style her hair. Also, she wears a long, black dress featured with a red ribbon and with knee long stocking and red ballerina shoes.


When she first appeared, she was like a doll with a very quiet personality. She only spoke when asked something and always followed her orders silently. However, even though she was an emotionless child, Hitomi felt she had no malice inside her.

After living a month with Hitomi and Hajime, it was noted she had aged mentally. She was very mature and curious of the things around her, finding "daily life" very interesting. And even though she was still quiet, she could speak her own mind and also use difficult and eccentric words, a trait Hitomi noted she gained from Hajime.



In order to end the Fifth Fairy War, the organization F, under the orders of the rogue fairy Zeion, created the strongest power user, capable of defeating every power user she faced. F named both her and her power as "System", because in a way, she could operate as the system of this world. Unlike others ability users, who were given their powers by the fairies, System was born with her powers, making her a very unique existence. Before her awakening, she was being kept asleep in a test tube inside a room in the Yuzuhara Food Proccesing Factory, which served as F's hideout.

In order to gain time to complete System, F created many rogue power users such as Tohei Yukawa and others with the intention to distract the War Management Committee and hide System's existence until she was ready to awaken.

Fallen Black vs F ArcEdit

Ino 05 143

System before her awakening

In the light novels, her existence was first discovered by Hitomi Saito, Aki Natsu and Hajime Kiryu when they infiltrated F's hideout. Even though she was still asleep in her tube, Aki was able to analyze her power, which caused her to temble with fear. Aki mentioned her power was cheating and there was no one who could beat her. The group decided to discuss System's existence later and fled the scene.

In Fallen Black's base, Reatier explained that System was created with the sole objective of defeating every ability user and end the war. For that purpose, her power was designed to get stronger after each battle, so she could be truly invencible.

With the war's future at stake, Fallen Black decided to attack F's hideout. Hitomi's plan to defeat System was to have Yanagi hack into the computer that was managing System's sleep and let her sleep forever. However, when Hitomi, Aki and Yanagi found System, it was too late. She had awakened earlier than expected. The group saw her floating in the air, but when she noticed them, she quickly proceeded to attack. As she was about to kill Hitomi, Hajime appeared to stop her attack. System asked Hajime's reason for stopping her since he had asked her to destroy F in the first place. He told her that Hitomi and the rest were not F's members, they were his allies. Hajime explained that System had joined Fallen Black after he gave her some candy in exchange, shocking everyone. Then, Hajime ordered them to destroy F, but as he was leaving, Hitomi noticed a horrible wound on his stomach. She correctly guessed it was a mark of the battle between him and System. Then, Hitomi commanded the rest of Fallen Black and charged into battle against F.

After F was completely annihilated by Fallen Black. System was renamed as Umeko Tanaka by Hajime and Hitomi and her appearance and hairstyle were changed by Aki. Since she had no place to stay, she usually stays in Hitomi's aparment.

Several weeks later, after Hajime's plan to kidnap "Root of Origin" failed, it was Umeko who took the unconscious Hatoko on her back and left her at Hitomi's place. She was present when Hatoko vanished and returned to the literature club's room.

Fallen Black vs Hearts arc Edit

In summer, when Hitomi and Hajime were discussing again because of his carefree way of living, Umeko, who had just returned from buying dinner, intervened and scolded them for making such a fuss even though they are adults. Hitomi noted that Umeko's mental age was older than hers. Then, Umeko decided to go out again to do the grocery shopping, but when Hitomi told her she would go instead, Umeko declined the offer. She mentioned that even though it didn't look like it, she enjoyed "daily life".

After some days, Hitomi and Umeko followed Hajime who had gone out mysteriously without saying where he was going. They followed him secretly to a hospital where they meet a nurse who happened to know Hajime.

Later, when they were returning home, they found Yanagi and Shugo, who have just been beaten by Hearts' members and were in a state beyond anger. When those two tried to leave without saying nothing, Hitomi ordered Umeko to stop them, which she did in a flash. After that, she scolded the two boys for making Hitomi worry and told them to just listen Hitomi because she could provide the answer they were looking for to calm their minds.

After Fallen Black defeated the organization known as Hearts, she was seen alongside Hajime and Hitomi giving Shizumu Sagami a ride in Hitomi's car to the hospital. After that, when she and Hitomi were on their way to home, she mentioned how she would like to observe the cherry blossoms, but when Hitomi proposed to go together in spring, Umeko said it was impossible. She revealed to Hitomi about her short lifespan and how she will not live for more than three months. She remembered her fight against Hajime at F's hideout and how he stopped fighting her when she told him about her limited lifespan. She asked Hitomi not to feel sorry for her and told her she was ready to accept her fate. Then, she smiled happily for the first time ever and thanked Hitomi, mentioning that she was grateful to both her and Hajime, because even though she was created as a murder weapon, she was able to live as a human thanks to them.

Last moments and Death Edit

One morning in autumn. Umeko was having breakfast with Hitomi. Hajime wasn’t there that day. Umeko begins to recall about how she was created as System and also about her short lifespan, remarking she only had one day left. Umeko notices that only two persons know about her short lifespan, Hajime and Hitomi. However, even they don’t know that she was going to die tomorrow. 

After breakfast, Umeko went to the supermarket to buy some candy. While she was returning home, she was lost in thought about her life. Then, she bumped into some dark-haired boy who happened to walk in front of her. Umeko helped the boy to pick the contents of his bag which were scattered in the floor. Umeko noticed some cards with names written on them, the boy just said they were cards of a naming card battle. Umeko noticed one card which title was "End of the World", so they talked about what they would do if the world was about to end tomorrow. In the end, the boy tells her, that if he was going to die tomorrow, he would like to leave regrets behind. Umeko didn't understand what the boy meant. After parting ways, Umeko returned home, but in her way, she found Genre Yusano outside Hitomi’s house. Genre asked where Hitomi was because she was not at home, so Umeko answered that she probably went to the supermarket.

Umeko asked Genre why she wanted to see Hitomi, so Genre said she intended to kill her. Umeko asked her why, but Genre just said it didn’t matter who she killed, it could be Hitomi or anyone. She just wanted to make clear her declaration of war to Hajime by killing one of Fallen Black’s members. Her plan was to pretend to be Fantasia in front of Hitomi or other member and then killed them by a surprise attack. When Genre was leaving, she took out her cellphone, trying to contact Hitomi by Line. However, at that moment, Umeko cut her phone in two pieces.

Ino 12 314

The battle between Genre Yusano and Umeko Tanaka

Genre asked her why she was doing that, even though she was going to die tomorrow. Umeko noticed she knew about her lifespan, but then, she told her while it was true she was going to die tomorrow, that’s exactly the reason why she wanted to do something today. Then, they had a battle. It was a battle between White Rulebook and Sex Eclipse. They fought at the sky and some minutes later, Umeko was able to beat Genre.

It was an obvious result, no matter what kind of power Genre Yusano uses, Umeko could adapt and awake new powers to counter her enemy’s powers. While fighting Genre, Umeko made sure to cause extra damage to the personality with a healing power, so Genre would not be attacking anyone for some time.

Ino 12 321

"I wanted to live more"

After successfully repelling Genre, Umeko was about to go home and wait for Hitomi, but then she lost power in her feet. She noticed that the battle against Genre took her remaining life. By using her power, she reduced even more her lifespan. Then, Umeko fell to the floor. At that moment, Hitomi appeared and went to her side. Even though it looked like Hitomi was saying something, Umeko couldn’t hear anymore. Umeko saw Hitomi crying, but then she also lost her eyesight, leaving her in darkness. However, she could still sense. She was feeling warm because of Hitomi hugging her and also could feel Hitomi's tears falling on her cheeks.

In her mind, Umeko finally understood the feeling of regret. She wanted to live more, that was the regret she was gonna leave behind. Umeko thanked that nameless boy from before for teaching her that. And even though her life was short, she remarked it was full of happiness.

Then, Umeko died peacefully with a smile in Hitomi’s arms.

Powers and AbilitiesEdit

White RulebookEdit

Originally, her power was known as System, but after joining Fallen Black, her power was renamed as White Rulebook by Hajime. Although it isn't stated in the anime, in the original light novels her ability is based on the concept of rock-paper-scissors, but with powers instead. Her ability would turn into whatever she needs it to be to help her in any situation, for example if a fire user were to attack her, her ability would become water, and if a lighting user came in to attack her in her water state, her water ability would just become pure water since pure water can't conduct electricity. Even if one were to kill her, her ability would become reincarnation.

Additionally, she has a tremendous strength, being able to lift a weight several times heavier than her own. Her speed, reflexes and combat skills are also incredible, being able to reduce two opponents in a flash.

In volume 9, it was revealed that using her power puts such a burden in her body that actually reduces her already short lifespan. For that reason, Hajime forbade her from participating in the war.


  • She became the sixth member of the Fallen Black.
  • Her favourite candy is Hi-Chew, a fruit-flavored chewy Japanese candy.
  • She recognizes Hajime as the greatest opponent she ever fought and also her equal.
  • The name "Umeko Tanaka" was a joint work between Hajime, who created the name, and Hitomi, who created the last name.
  • She was created with a short lifespan, because originally, her creator didn't have a use for her after ending the war.
  • She appears in the cover of volume 12.

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