Officer Serious
Civilization(s) LightLight
Affiliation Rare Killers
Voice Actor 小山 力也
Rikiya Koyama
Signature Card(s) Jelvis, D2J
Jail House Lock, Jail of D
Dekodekko Dekorianu Pikkappikka III, Brave Dragon Elemental

Officer Serious is a member of the Rare Killers and is the 9th member.


A tall and indimitating-looking figure that resembles a prison warden and has patterns of keyholes all over his clothes. His face is obscured by a black shade. As his name suggests, he is very cold and humorless. He is a very efficient Rare Killers member, often being able to steal more rare cards than other members did.

When he was a kid, he was kind but foolish as he returns with bigger presents when received with presents (such as giving a fish for a piece of chewing gum), so people often laughed at him. As a result, he realized that his good heart has no repay and thus became a prison warden of his own fashion. After warming up due to comedians Hajiraccho and Bageraccho, he decided to leave the Rare Killers. His wish when he was young, which he forgot until his second duel against Katta, is to become a Comedian. He even became a comedian himself after the Dormageddon X incident.

Despite his intimidating appearance, he is actually only 27 years old.


He was at first seen filming a video about Katta with NOZOKIN. After Katta makes a few videos, he comes in, sticks Katta's eyebrows with black tape then sends him into a prison along with NOZOKIN and Hokaben. He then indicts Katta, Nozokin and Hokaben of making disgusting videos such as Hokaben drawing cards with his snot, then proceeds to bring Ta-Kun and a woman holding his cart to meet Katta. All was interrupted when Lulu Takigawa broke the prison wall and proceeds to have Katta challenge him into a duel.

In a duel he uses numerous shield feed spells to take away Katta's creatures and uses Alcadeias, Lord of Spirits to lock his spells. He then sends out multiple Jelvis, D2J with a low cost as Katta already has numerous shields due to its cost reduction. However, when he broke all of Katta's shields, Katta sent out Dogiragon Buster, Blue Leader via Bosskatsu Buster, No.2 Man and he was defeated.

After his defeat, Katta was transported out of the prison by a helicopter.

He later performed a second operation where he attacked Katta's School and hypnotized people by smashing them with books. Only now he was confirmed to be Rare Killers by words. Then he was confronted by Katta and 2 comedians Hajiraccho and Bageraccho (As shown in corocoro's commercial breaks between episodes) and imprisoned all of the people save for Katta and Bageraccho and dueled Katta. In the duel he imprisoned all of Katta's creatures, Including the entire Team Hamukatsu with Jail House Lock, Jail of D and spammed 4 Jelvis, D2J with the reduced costs which broke all of Katta's shields. However, one of the shields was a Holy Awe added to Katta's deck by Bageraccho then Bageraccho proceeds to draw Dogiragon Buster, Blue Leader and defeated him.

Serious Stripped

A fully stripped and dancing Officer Serious

After then his cold and humoreless personality was broke and he decided to leave the Rare Killers.

Upon leaving the Rare Killers, Serious goes back to the Rare Killers base and notify Basara about this, then he strips all of his clothes until his underwear remains and challenges Basara to a duel. In the second turn he strips off his hat as well and reveals his bald head, dances while sending out Dekodekko Dekorianu Pikkappikka III, Brave Dragon Elemental which has entertained the Rare Killers mobs. This has angered Basara and Basara finishes him off with a ZERO Charge Kill. After his defeat, he appears in Dragon Ryu's food store.

After Basara's release from possession by Katta, he became a comedian, working with Ta-Kun.


  • "Majime" (まじめ) is Japanese for seriousness.
  • He did not demonstrate Jelvis, D2J's D2 Field limited effect in his first duel; instead, he spammed them and treated them as spammable beatsticks.
  • He is not seen to be directly commanded by Basara or Number 2 throughout his first action.
  • Additionally, he does not seem to be present during the Rare Killers gathering during the VSR epilogue.
  • He is the first Rare Killers member to officially leave it.
  • The top part of his head is actually bald with only 3 strands of hair.



Episode number Opponent Outcome Deck name
Episode 18 Katta Kirifuda Loss All of you guys feeding prison
Episode 28 Katta Kirifuda Loss All of you guys feeding prison
Episode 29 Basara Loss All of you guys sending me laughter

He uses a mono Light deck focused on Angel Commands and Initials, which he named "All of you guys feeding prison".

Once he betrays the Rare Killers, his new deck focuses on spamming Angel Commands which he named "All of you guys sending me laughter".

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