Under Night In-Birth Wiki


Phonon (フォノン)
Yoshiko (良子(ヨシコ))




August 5th


157 cm (5'2")


45 kg (99 lbs)


Bust: 78cm [1]
Waist: 57cm
Hip: 82cm





Cleaving Flurry [Chemeti]


A former member of EFG

Battle Style


The EXS of Resonance: Baroque Noise



Voice Acting

Japanese Voice:

Saori Onishi

"Might as well use this awakened manga
hero power to its fullest. No use wasting
something so cool, right?"

Phonon (フォノン) is an unallied In-Birth who has recently awakened to her powers. She is a third-year middle school student and an aspiring writer who admires all kinds of supernatural things.

She first made her debut in the arcade launch of UNDER NIGHT IN-BIRTH Exe:Late[st].


Adrift in a world of mystery, the "Chemeti"

Having a strong sense of power, Phonon leaves the EFG, a student self-defense force known for their strict rules, so she can use her powers more freely. Her behaviour is not unlike a normal student's, going through a sensitive stage and wanting to find their "true self" amid the exhaustion of daily life. She believes her In-Birth powers are proof of awakening to her true self. As such, she uses her power against other under the darkness of night. Little does she know that there is someone else who also moves shadows who knows her "false self" from before she awoke.[2]


Phonon's real name is Yoshiko (良子), but her surname is unknown. Phonon is a pen name that Yoshiko used in her younger days, believing that is the true name of her soul.


Phonon is a slim, young girl with green hair and grey eyes. Her attire consists of a grey, two piece waistcoat, with a pink, long-sleeve dress with black streaks around the bottom and middle sections. The bottom of the dress is adorned with small, black frills. Her legwear consists of a pair of black and white striped leggings and a pair of black stilettos. She also wears a pair of red headphones to stop her from harming herself with her own powers.

Her school uniform is almost identical to one worn at Nanase's school, down to the green shirt, short skirt and cravatte, which she wears more loosely. A big difference is that she wears a light grey, unbuttoned blazer over the shirt with black rimmed lapels. She also wears a pair of completely black leggings.

Phonon's original hair color was black, but it was most likely dyed green before the main story.

When trying to hide her identity from Nanase, Phonon dons an incredibly paper-thin disguise consisting of a black opera mask for her and a pink ribbon and lipstick for Muniel.


Most of the time, Phonon seems to be very wise-cracking and is quick to look down on other people through a harsh and demeaning front. However, she is deeply obsessed with supernatural phenomena and willingly risked her life to become an In-Birth (which are common traits of middle-school syndrome). During the Hollow Night, she puts on the role of a dominatrix, which can sometimes lead to some awkward situations.

Phonon is also a very bad liar, as Tsurugi was able to completely see through her act even if he didn't do any research beforehand. She also tends to be very easily sensitive towards her real name or anything to do with her mundane life, as well as having a one-sided vitriolic dynamic towards Nanase even if the very latter is genuinely acting nice towards Phonon; despite this Nanase easily angers her whenever she speaks out her real name ("Yoshiko").



In grade school, Phonon was good friends with Nanase, due to them originally having very similar interests. However, their friendship started to grow distant when Phonon moved to middle school, with Nanase moving to a different school a year later.

Episode: A False Identity, A True Self (偽りの身分、本当の自分)
About two months before the actual story takes place, Phonon starts to hear rumors about the Hollow Night and the "shadows" that grant people mystical powers. Her curiosity leads her to the check if the rumors are real by listening in on conversations between other students during school hours, though an emergency assembly regarding the ongoing rumors and warning students about wandering alone at night interferes with her schedule.

After school, Phonon heads out into city during dark hours to search for the rumored shadows in a nearby park, but the unsettling atmosphere and darkness cause her to give up and head home through the shopping district. While there, Phonon overhears a group of female students talking about how a second-year student got attacked near a shrine, reinvigorating her.

Phonon goes to look for the shrine, but ends up getting lost in an abandoned back alley. While trying to find her way out, she gets hit with a sudden feeling of nausea and realizes that she has entered the Hollow Night. Shortly after entering the Night, Phonon is discovered and is bitten by a Void despite her attempts to escape, though she is soon able to break free from the Void's grasp and runs away as fast as she can, barely escaping with her life. Phonon makes it back to the shopping district and is asked as to what happened by a concerned woman, but Phonon simply brushes it off as being attacked by a large dog. Once the woman leaves, Phonon finally decides to head back home but ends up collapsing from fatigue.

Two days later, Phonon tries to head back to school after being called in for questioning, but her mother tries to send her back to bed; Phonon, however, manages to convince her mother to let her go in for questioning on the afternoon. After being questioned by staff, she heads home. The next day, Phonon has fully recovered and spends the majority of her day back at school. After school, Phonon ponders whether to head back to the Hollow Night or not, but eventually decides against it.

While walking towards the school gates, Phonon is approached by two people from another school named Tsurugi and Komatsu. Tsurugi deducts that Phonon has become an In-Birth after looking through the attendance records for her school and manages to see through the lies she comes up with. Soon, Phonon cracks and admits to wandering into the Hollow Night. Tsurugi offers her to come with him and Komatsu to their headquarters at their own school, to which Phonon begrudgingly accepts.

When they arrive at the school's Student Council headquarters, Tsurugi and Komatsu explain that they are members of the EFG, a vigilante organization that consists of school students who have become In-Births after wondering into the Hollow Night. Tsurugi also explains the basics of the Hollow Night and how EXS works to Phonon, who's only really interested in her powers. Seeing how excited she is, Tsurugi offers her a weapon in exchange for her services in the EFG; A shape-shifting Void fragment called Meuniel, which transforms into a whip for Phonon. Phonon gladly accepts the weapon, but has to be stopped by Tsurugi after getting too over her head with her new weapon while in the EFG headquarters.

Tsurugi then explains to Phonon that EFG has very strict guidelines when it comes to students using their powers within the organization. Students are not allowed to use their powers unless it is specifically needed, and that abusing their powers will result in them being classed as an enemy by the EFG. Despite these guidelines, Phonon begrudgingly acceps and joins the EFG, but secretly plans to leave once she has learned the ropes of her abilities and the Night. Outside of the school, Phonon parts with Tsurugi and Komatsu, promising to master her powers. A month later, she leaves the EFG.

Arcade Mode (アーケードモード)
A month after Phonon leaves the EFG, she decides to head out into the Hollow Night to test out her powers after narrowly escaping some fellow In-Births.

During her ventures into the Hollow Night, Phonon comes across Hyde, who tries to strike up a conversation regarding their specific weapons and the history of them. However, Hyde's happy-go-lucky nature when talking about Meuniel causes Phonon to lash out in frustration, starting the fight between the two, to which Phonon emerges the victor.

Later on, Phonon comes across Gordeau, who at first mistakes her for Licht Kreis' Crimson Knight, but quickly gets over it when he sees that Phonon's harsh, dominating behavior is an act. Gordeau likens Phonon's harsh demeanor to Hilda, but quickly backpedals on his statement when Phonon takes an interest in meeting her. Despite Gordeau's attempts to convince Phonon to give up the act, she ends up challenging him to a fight in order to figure out the location of Hilda. The two fight, with Phonon emerging victorious.

Phonon finally makes her way to the Altar of Light and Darkness, where she meets Hilda. Phonon tries to put on her domineering persona, but ends up enraging Hilda by calling her old, causing her to attack Phonon. Hilda soon calms down, however, and begins talking to Phonon about her past with EFG, though she simply brushes them off as "goodie-two-shoes". Intrigued by Phonon's attitude towards the faction she worked for, Hilda challenges her to a fight.

As soon after Phonon defeats Hilda, Nanase barges into the Altar, demanding a fight with Paradox. Nanase ends up spotting her childhood friend, calling out to her by her real name. This ends up scaring Phonon, who doesn't recognise Nanase at first due to her having a more feminine look. Nanase's repeated use of Phonon's real name starts to anger the Chemeti, and it isn't long until she reaches her breaking point and threatens to erase all of Nanase's memories of her.

After a brief scuffle, Phonon is able to knock Nanase unconscious and carries her out of the Altar to somewhere safe. In order to keep Nanase from recognising her, Phonon dons herself with a paper-thin disguise. Nanase wakes up, believing that Hyde attacked her, but is unable to remember much else, much to Phonon's glee. Nanase thanks Phonon for her supposed help before heading back on her way. Finally alone, Phonon expresses her satisfaction with the results of her powers, but notes to be wary of Tsurugi and the rest of EFG. Meanwhile, Nanase watches Phonon from a distance, revealing to have faked her memory loss.


Phonon's EXS ability is the EXS of Resonance (振鳴のEXS): Baroque Noise (バロックノイズ) This ability grants her the power to manipulate sound waves, turning them into shockwaves, projectiles and even letting her break the sound barrier via her whip. However, her abilities have the sound effect of potentially harming her, which is nullified via the use of headphones..

Her whip in particular is actually a being called Muniel (ムニエル); A Void fragment whose true form is that of a white snake. Muniel was able to take the form of a whip after Phonon endowed it with her EXS; before that, it took the form of a pair of scimitars wielded by Komatsu.

When paired with Muniel, Phonon is a powerful fighter, using a mixture of her whip and acrobatics as well as her Baroque Noise ability to attack from a distance.

Musical Theme

Title Description
Sound of Night Wind Phonon's theme

Title Description
Sound of the Night Wind Phonon's theme

Composer Commentary

Sound of Night Wind
After seeing the character visual, I was kinda troubled at what kind sounds should I make. In the end, I settled to taking inspiration from the sprite art.

I feel like the themes of female characters have quite a wide range range compared to the male ones.[3]

Sound of Night Wind


Introduction Text

She wishes. She yearns for powers beyond the ordinary. Trailing along beside her
is a white follower. She waits for the time to awaken from her false self,
and awaken she does. The sword speaks to her on a path leading to a bright future,
but she turns in another direction, only to find the sword blocking her way.
A way that trails from a murky past over which she has trampled.

She wishes. For the paranormal ability from the deepest spirit of hers. Along with the
white follower. False shell at present. The wish will be fulfilled when the time comes right
here. The sword speaks. The path to the bright future. She fails. The sword exposes. The
path from the cloudy past. She overrides.



Name Command
Unique Attacks
Unique Attack
← + B
Unique Attack
↘ + C
Unique Attack
Midair ↓ + B
Unique Attack
Midair ← + B
Unique Attack
B > B
Force Function
Impulsive Frustration
Simultaneously B + C
Special Attacks
Sliding Affliction
↓↘→ + A or B or C
Air OK *EX Able
Tuning Satisfaction
↓↙← + A or B or C
*EX Able
→ Additional Input
← + A or B or C during Tuning Satisfaction
Guiding Ascension
→↓↘ + A or B or C
*EX Able
Suppressing Restriction
↓↓ + A or B or C
*EX Able
Infinite Worth (Consumes 200% EXS)
Binding Beatitude
←↙↓↘→ + D
Infinite Worth EXS (Consumes 200% EXS)
Totally Dominating Servitude
A · B · C · D simultaneously
Usable when below 30% health

Check the details about Phonon's gameplay from here!


Official Art
Character Select
Victory Portrait
SD Character
Ed pho.jpg
Arcade Mode Ending
Official Illustrations
Happy Birthday by Seiichi Yoshihara (2015)
Happy New Year by Seiichi Yoshihara (2016)
Valentine's Day by Yusano (2016)
Happy Birthday by Koutarou Shiratori (2016)
Happy Birthday by Takehiko Wagatsuma (2017)
Happy Birthday by Yuusuke Nakahara (2018)
Happy Birthday by Seiichi Yoshihara (2019)
Phonon 2020.png
Happy Birthday by Seiichi Yoshihara (2020)
Concept Art
Scrap chemeti.png
Concept sprites from Mook
Sprites shown in Game★Maniacs[4] program
Initial concept art from Exe:Late[cl-r] gallery
Initial concept art from Exe:Late[cl-r] gallery
Concept art from Exe:Late[cl-r] gallery
Store Icons
Character colors 4.jpg
Additional colors (Playstation Store)
Character colors 8.jpg
Additional colors 2 (Playstation Store)
Phonon system voice.jpg
System Voice (Playstation Store)
System voice all in one.jpg
System Voice all-in-one (Playstation Store)
Gameplay Tutorial for Exe:Late[st]

Creation and Development

Phonon was originally revealed in a teaser picture posted on French-Bread's blog long before the final character roster was confirmed. Her concept art was later featured in the Exe:Late[st] End of Dawn Edition artbook.

After that, she was then seen in the Start-up Navi in the section where they showcased the scrapped ideas. It was revealed in here, that Phonon's design started from the battle planner Kamone Serizawa's random ideas.

Character designer Yoshihara Seiichi's comment from Mook:

You read it as 'Shumeti'. This character was based on idea that Kamone from the development staff gave. Her hearing ability was extremely good, but on the other side her eyesight was low and her eyes were always squinted. She also possessed quite a sharp tongue and highly sadistic personality. Her pet snake would transform into a whip and she was also granted the ability to control waveforms. With those two in her use, she would have whipped her opponents (supposedly). There were certain reasons why she ended up being scrapped.


On October 10th 2014, during French-Bread's UStream broadcast, Nobuya Narita answered fans questions. One fan asked if it was impossible to bring back the scrapped "Chemeti", which the producer commented that it's not totally impossible and that they'd have to get over certain problems to bring her back.

"Filthy *beep*!"

On May 15th 2015, Arc System Works announced Exe:Late[st] and the newly designed Phonon. When the game officially came out, French-Bread released a celebratory video in which they joked how Eltnum and Nanase had delayed Phonon's appearance even though she was created first.

Upon on her release, it was revealed that Phonon's background setting had been adjusted. Her bad eyesight trait had been removed as well as the glasses she wore in some of the concept art. Phonon's sadistic personality was also changed to something more resembling that of a regular high-school student who likes paranormal media and tries hard to mimic various cool traits.

It was revealed during an early development that Gordeau was originally planned to be Phonon’s older brother, due to also using a snake-based weapon like her. However, Gordeau’s early concept was debunk and redesigned as both different person and scythe wielder.


  • Phonon's music theme was originally going to be named "Sound of Silence" as revealed in "UNIst Music Stream" held on August 20th 2015
  • Phonon's title, Chemeti, was the original name given to her in concept, as seen above.
  • The size of Phonon's shoes is 23 (JP scale) which is equivalent to "37" EU or "6½" US
  • Muniel is mistranslated as “Moony” in the localized version of the Exe:Late[st].
  • A phonon is a quasiparticle that is associated with compressional waves, which includes sound.


  1. Revealed in her gameplay tutorial video. Not written in any official materials.
  2. Introduction on the official site
  3. Raito's Youtube Channel
  4. Game★Maniacs archive (Originally broadcasted July 27th 2017)


Playable Characters
Guest Characters
Non-Playable Characters