Editing Yu-Gi-Oh! OCG Structures - Chapter 003

{{Infobox chapter
| image           = OCG Structures 003.png
| ja_name         = {{Ruby|光|ひかり}}と{{Ruby|闇|やみ}}
| romaji_name     = Hikari to Yami
| ja_trans_name   = Light and Darkness
| series          = Yu-Gi-Oh! OCG Structures
| number          = 3
| ja_magazine     = V Jump
| volume          = 1
| ja_issue        = 2019 #10
| ja_release_date = August 21, 2019
}}

"'''Light and Darkness'''" ({{Ruby|光|ひかり}}と{{Ruby|闇|やみ}} ''Hikari to Yami'') is the third chapter of the ''[[Yu-Gi-Oh! OCG Structures]]'' manga. It was first published August 21, 2019, in the ''[[V Jump]]'' magazine.

{{Chapter summary|After a harmless misunderstanding, [[Shoma Yusa|Shoma]] now finds himself in a Duel against the (self-proclaimed) servant of darkness - [[Yami Kuroda|Dark Kuroda]].}}

== Summary ==
It has been three months since [[Shoma Yusa]] first arrived in Tokyo and participated in his first Deck Construction event. Shoma sits in his room, where his sister [[Ageha Yusa|Ageha]] is trying to get his attention, to no avail. Shoma is lost inside his own little Structure World, where he's having a lively chat with mental projections of his cards to figure out how to improve his "[[Tenyi]]" Deck. After having collected the Tenyi Spirits he missed during the ''[[Rising Rampage]]'' event, as well as two [[Draco Berserker of the Tenyi (OS)|new]] [[Draco Masters of the Tenyi (OS)|monsters]] that were released recently, he declares that his Deck is finally perfect.

The next day, Shoma visits the [[Satellite Shop]], where he finds his best (and only) friend in Tokyo [[Jukyu Goriki|"Strong" Jukyu Goriki]]. He invites Jukyu to Duel, but Jukyu, as his friend, points out that he shouldn't constantly be Dueling against a single person. Shoma doesn't have any other friends in Tokyo despite living there for three months, so Jukyu encourages him to take a chance on someone else. Looking around, Shoma does notice a potential Duel partner, and tells Jukyu he's going to take a chance on the girl with the [[White Potan|Potan]] bag playing by herself. Jukyu cheers him on, but recognizing that description, he realizes too late that Shoma has perhaps taken a chance on the wrong person.

Shoma approaches the girl sitting by herself and, mustering his courage, meekly asks if she would like to Duel with him. At that moment, a voice from the shadows of this well lit card shop, calling himself the moonlight that illuminates the dark night that apparently is this bright and sunny day. The voice is coming from another teenager wearing a black costume and two leather belts. His beloved little sister [[Tsukiko Kuroda|Tsukiko]], he declares, hasn't come to this nest of rats and vipers to be chased after by those who dwell within. For this transgression, he, the servant of darkness [[Yami Kuroda|Dark Kuroda]], challenges Shoma to a Duel for his sister's honor.

Jukyu protests, saying that Shoma is new in town and wouldn't know about Kuroda or his sister. Kuroda asks Jukyu the cur if the scoundrel is with him, and Jukyu continues that all Shoma did was innocently ask his sister for a Duel. But Kuroda declares that she the light to his darkness, and that darkness and light cannot exist without the other. Trying to take away the light is therefore a heinous crime, and must be punished. Jukyu decides they don't have to deal with this, and tells Shoma that he'll Duel with him after all. Shoma, however, states that he still wants to Duel Kuroda.

Jukyu is stunned, stating that the siblings are nothing but trouble, but Shoma is taking a chance on Kuroda. Tsukiko watches in silence, thinking that Shoma will regret challenging her brother, and calling the entire situation foolish. The Duel begins, and Kuroda states that now the curtain will rise on the revelry of darkness. Jukyu is confused by his choice of words, as the Solid Vision system in their Duel Disks has projected them into a field with a clear blue sky.

Kuroda quickly uses his "[[Mathmech]]" cards to gather two Level 4 monsters on his field, which he uses to open the Overlay Network. "O, operator of arithmetic made of lies," he declares, "Crush the mindless fool before me with your electromagnetic waves!!" So does "[[Primathmech Alembertian (OS)|Primathmech Alembertian]]" appear. But Kuroda merely uses his Xyz Monster as a stepping stone to fill his field with three Level 4 monsters, one of whom is a Tuner. He tunes two of his Level 4 monsters together to Synchro Summon a monster. "O Mathmech Knight, with blazing red-hot sword at the ready," he declares, "Exterminate my foes with that blade clad in flames!!" And so does "[[Geomathmech Magma (OS)|Geomathmech Magma]]" appears.

Jukyu, while appreciating the work Kuroda put into his [[summon chant|summoning speeches]], tells him to hurry it up. Kuroda retorts that outsiders in this Duel should hold their tongue. Finally, he Tunes his remaining Level 4 monster to his Level 8 Tuner Synchro "Final Sigma" to Synchro Summon his most fearsome "Mathmech" monster. "O highest Mathmech Knight, who wields the crimson-dyed sword," he declares, "Conquer the flames and destroy my foes with your blade!!" And with that completely unnecessary bit of drama, "[[Geomathmech Final Sigma (OS)|Geomathmech Final Sigma]]" appears. To end his turn, Kuroda equips his monster with "[[Mathmech Billionblade Nayuta (OS)|Mathmech Billionblade Nayuta]]".

Shoma is impressed by the Kuroda's monster, and notes to himself that while in the [[Extra Monster Zone]], it is unaffected by card effects. He decides that in that case, he'll have to find a way to overpower it completely. Tsukiko notes that if attacked, Kuroda can still use "Nayuta" to increase his monster's power, potentially rendering Shoma's efforts moot. Shoma begins his turn, and begins making plans to remove Kuroda's Equip Spell. At that moment, Kuroda addresses Shoma directly. He declares that with his right hand, aching from the power flowing through it, he shall cut Shoma's lowly Deck in twain. Shoma dared to approach with impure intent, and for this revolting act, there will be consequences.

Jukyu states that Kuroda was also one of the Four Duel Kings in elementary school, and the greatest among them. He also states that he was a tremendous pain to deal with, not only for his skill, but for his incredibly over-the-top imagination, grandiose delusions, and very tenuous grasp on reality. Tsukiko agrees, saying that her beloved older brother is quite embarrassing to be around.

== Featured Duel: Shoma Yusa vs Dark Kuroda ==
<u>'''Turn 1: Kuroda'''</u><br />
Kuroda [[Normal Summon]]s "[[Mathmech Sigma (OS)|Mathmech Sigma]]" (L4/1000/1500). He then [[activate]]s the [[effect]] of "[[Mathmech Subtraction (OS)|Mathmech Subtraction]]" in his [[hand]], targeting "Mathmech Sigma" on the field and [[Special Summon]]ing it (L4/1000/1000) to his field in [[Attack Position]], then reducing the [[ATK]] of the targeted monster by 1000 ("Mathmech Sigma": 1000 → 0 ATK). Kuroda overlays his two [[Level]] 4 [[Monster Card|monster]]s to [[Xyz Summon]] "[[Primathmech Alembertian (OS)|Primathmech Alembertian]]" (R4/2000/0) into the [[Extra Monster Zone]] in Attack Position.

He activates the effect of "Alembertian", [[detach]]ing its two [[Xyz Material]]s to add a "[[Mathmech]]" monster from his [[Main Deck|Deck]] to his hand. He adds "[[Mathmech Addition (OS)|Mathmech Addition]]". He then activates the second effect of "Alembertian": by [[Tribute|Tributing]] a monster he [[control]]s, he can Special Summon a "Mathmech" monster from his hand or [[Graveyard]]. He Tributes "Alembertian" itself to Summon "Mathmech Subtraction" from his Graveyard. As he controls no monsters in his Extra Monster Zone, he also activates the effect of "Mathmech Sigma" in his Graveyard, Special Summoning it in Attack Position, but he must [[banish]] it when it leaves the field. He then activates the effect of "Mathmech Addition" in his hand, targeting "Mathmech Sigma" he controls and Special Summoning it (L4/1000/1000) to his field in Attack Position, then increasing that targeted monster's ATK by 1000 ("Mathmech Sigma": 1000 → 2000 ATK).

Kuroda tunes the Level 4 "Mathmech Addition" to his Level 4 [[Tuner monster|Tuner]] "Mathmech Sigma" to [[Synchro Summon]] "[[Geomathmech Magma (OS)|Geomathmech Magma]]" (L8/2500/0) into the Extra Monster Zone in Attack Position, with "Mathmech Sigma" being banished instead of sent to the Graveyard. He then tunes the Level 4 "Mathmech Subtraction" to the Level 8 [[Tuner Synchro Monster]] "Geomathmech Magma" to Synchro Summon "[[Geomathmech Final Sigma (OS)|Geomathmech Final Sigma]]" (L12/3000/0) into the Extra Monster Zone in Attack Position. While in the Extra Monster Zone, "Final Sigma" is unaffected by non-"Mathmech" card effects, and any [[battle damage]] it inflicts from a battle with an opponent's monster is doubled. Kuroda activates "[[Mathmech Billionblade Nayuta (OS)|Mathmech Billionblade Nayuta]]", equipping it to "Geomathmech Final Sigma". If the equipped monster battles an opponent's monster, Kuroda can send a "Mathmech" monster from his Deck to the Graveyard to increase his monster's ATK by that sent monster's. 

:''Duel continues in the [[Yu-Gi-Oh! OCG Structures - Chapter 004|next chapter]].''

== Featured cards ==
The following cards appeared in this chapter. Cards in italics debuted here. 

{{Decklist|Shoma Yusa
| effect monsters = 
* ''[[Tenyi Spirit - Ashuna (OS)|Tenyi Spirit - Ashuna]]''<ref name="hand">This card is seen in Shoma's starting hand.</ref>
* [[Tenyi Spirit - Mapura (OS)|Tenyi Spirit - Mapura]] x2<ref name="hand"/>
| tuner monsters = 
* ''[[Jet Synchron (OS)|Jet Synchron]]''<ref name="hand"/>
| synchro monsters = 
* ''[[Draco Berserker of the Tenyi (OS)|Draco Berserker of the Tenyi]]''<ref name="possession">This card is seen among Shoma's owned cards.</ref>
| link monsters = 
* ''[[Draco Masters of the Tenyi (OS)|Draco Masters of the Tenyi]]''<ref name="possession"/>
* [[Monk of the Tenyi (OS)|Monk of the Tenyi]]<ref name="possession"/>
* [[Shaman of the Tenyi (OS)|Shaman of the Tenyi]]<ref name="possession"/>
| spells = 
* [[Vessel for the Dragon Cycle (OS)|Vessel for the Dragon Cycle]]<ref name="hand"/>
| traps = 
* [[Waterfall of Dragon Souls (OS)|Waterfall of Dragon Souls]]<ref name="hand"/>
}}

{{Decklist|Dark Kuroda
| effect monsters = 
* ''[[Mathmech Addition (OS)|Mathmech Addition]]''
* ''[[Mathmech Subtraction (OS)|Mathmech Subtraction]]''
| tuner monsters = 
* ''[[Mathmech Sigma (OS)|Mathmech Sigma]]''
| synchro monsters = 
* ''[[Geomathmech Final Sigma (OS)|Geomathmech Final Sigma]]''
* ''[[Geomathmech Magma (OS)|Geomathmech Magma]]''
| xyz monsters = 
* ''[[Primathmech Alembertian (OS)|Primathmech Alembertian]]''
| spells = 
* ''[[Mathmech Billionblade Nayuta (OS)|Mathmech Billionblade Nayuta]]''
}}

{{Decklist|Shoma's imagination
| effect monsters = 
* ''[[Gemini Imps (OS)|Gemini Imps]]''
}}
<references />

{{Yu-Gi-Oh! OCG Structures chapters}}