Earphone Jack

Earphone Jack
Quirk Information
Japanese Name	イヤホンジャック
Rōmaji Name	Iyahon Jakku
Quirk Description
User	Kyoka Jiro Mika Jiro
Quirk Type	Mutant
Quirk Range	6 meters
First Appearance
Manga Debut	Chapter 11
Anime Debut	Episode 8

This article is about the Quirk. For the Class 1-A student whose hero name is named after this Quirk, see Kyoka Jiro.

Earphone Jack (イヤホンジャック, Iyahon Jakku^?) is the Quirk used by Kyoka Jiro and her mother, Mika Jiro.

Description

Kyoka can detect the presence of something by the sound they emit.

Earphone Jack grants its users long, controllable earlobes that work like headphone cables. Kyoka's earlobes are shaped like jacks at their ends, allowing her to plug them into a variety of objects. Those earlobes can further channel the vibrations of Kyoka's own heartbeats, dealing internal damage to said objects.

Moreover, Kyoka is able to catch faint sounds through her jacks even across extremely thick walls, making her excellent at scouting work. It is possible, however, to mislead her by somehow generating multiple sources of noise to mask the ones she's trying to detect.

Kyoka extending her earlobes.

Kyoka's earlobes can stretch up to 6 meters, and the radius of detectable sound is 12 meters. They are sturdy enough to easily pierce hard materials like concrete and able to act as additional limbs due to their prehensile nature, with Kyoka being capable of picking up small objects with them.

It's unknown if Mika has access to all aforementioned abilities displayed by her daughter.

Weaknesses

Like any other part of her body, however, the Earphone Jacks are susceptible to damage and may suffer from overuse, evidenced when Kyoka's ears began to bleed from using her Quirk too much in a short time frame during the First Term Final Exam.

Kyoka's Quirk Factor lies within her ears and due to her losing her left ear during the battle against All For One, the use of her Quirk is now limited to just her right ear.

Usage

Earphone Jack being used on a phone.

Kyoka uses her Quirk mostly for spying or support, making use of her jacks to detect vibrations caused by enemy movement. For offense, Earphone Jack can act as a sort of whip, with Kyoka using her jacks to shock targets with vibrations.

Kyoka can plug the jacks into the boots of her hero costume, which have speakers that allow her to shoot a concentrated blast of sound from her heartbeats in a specific direction. This technique, however, can be countered with a louder, opposing source of sound, such as Present Mic's Voice Quirk.

Earphone Jack is able to emulate actual headphones, evidenced by Kyoka plugging her jacks into electronic devices in order to listen to audio in private.

Named Ultimate Moves

	Counter-Balance (カウンターバランス, Kauntābaransu?): Using the amps on her legs, Kyoka is able to create sound waves to counter attacks.
	Heartbeat Distortion (ハートビートファズ, Hātobīto Fazu?): Using special sound-amplifying items located on her forearms, Kyoka plugs her jacks into those amplifiers and slams them onto the floor, channeling a powerful heartbeat that causes the ground to shatter due to the enhanced vibrations.
	Heartbeat Surround (ハートビートサラウンド, Hātobīto Saraundo?): Using the same sound-amplifying items from her Heartbeat Fuzz technique, Kyoka uses her jacks to remove the equipment pieces from her wrists and aim them towards a target, channeling a loud heartbeat that ignores conventional defenses and incapacitates foes.

Legato (レガート, Regāto?): Kyoka uses her amplifying equipment to channel a loud heartbeat directly at her opponent on a larger scale, with more power, and with more sound generated.

Heartbeat Wall (心音 (ハートビート) 壁 (ウォール) , Hātobīto Wōru?): Similar with Heartbeat Surround, Kyoka uses her jacks to move her sound-amplifying items and aim towards a target. She channels sound to form a wall to block enemies. She first used this move against Izuku Midoriya.

Trivia

• Kohei Horikoshi mentions that Kyoka's Quirk is possibly the first Quirk he came up with, far before he'd even started planning My Hero Academia.