| Oka Reiko |
|Family||Dragon Ryu (Friend)|
|Voice Actor|| 松来未祐 |
|Signature Card(s)||Dead Ryusei, Eternal Demon Dragon, Fusshisshi the Invulnerable, Hachinosu Batchikuma|
While being a seemingly affectionate person when Dragon Ryu is near, she is actually an extremely dangerous person who attacks anything who gets near when he is absent.
She is a ghost Dragon Ryu encountered when he was working as a ghost buster. She later accompanied Dragon Ryu and worked as his assistant in his oden store "Donguri-ya". She first made an appearance with Ryu in episode 8 helping him to clean the utensils and Katta Kirifuda noticed her. She supported him during his duel against Katta.
In episode 17 she dueled Katta in Dragon Ryu's house and used a monocolored Darkness deck. However Katta defeated her by using his Gaial Mobius, Victory Emperor. She retreated to the room and both she and Dragon Ryu gave Katta and his friends a surprise party. It was revealed that she dueled Katta in order to buy time for Ryu to prepare for the surprise party and scares Hokaben to get him out of the way.
In episode 30, she, Dragon Ryu and Katta were brought to a deserted island by a mysterious man,who was none other than Shobu Kirifuda. On the second day she supported Ryu and was also part of the duel. Both of them lost to Katta's new Dragheart cards and left the island by motorboat after Katta and Hamukatsu fell under the canopy trap. She and Ryu watches the New Year 3-on-3 exhibition match.
In Katta's final duel against Lucifer, she cheers for Katta.
- Her voice actor, Miyu Matsuki, passed away on October 27, 2015, at the age of 38 due to "An illness that must be cured early". The name of the illness is not revealed to the public.
Benchan ● Yohdel ● Lucifer ● Kojiro Sasaki ● Justice
Helen ● Sasori Busujima ● Dragon Ryu ● Hamukatsu
Oka Reiko ● Komei ● Gyou ● Hattori ● Lena
Dobin Sensei ● Shobu Kirifuda ● Mai Kirifuda ● Benny Haha