|“||Bring it on - Go to work!||”|
—Sei'ei's usual catchphrase.
She is a medium-tall girl with cerulean eyes and long yellow hair tied with white band. Her attire consist of a white undershirt and a blue overshirt, and a black skirt with white long sock and plain black shoes. She also has a necklace with an empty oval frame in it, and a gold earring on her right ear.
Her core gadget is an a blue oval gem that fits into her necklace. When it activates Future Force, it only glows red with no other changes.
After she joined the Buddy Police, she gains a Buddy Police crest that she wears at the left corner of her shirt.
She is first shown opening a Magic World pack, and managed to pull a Buddy Rare. Unfortunately, it was a Dragon World card that is put into the pack by mistake - "Purgatory Knights, Death Sickle Dragon". Sei'ei sit on a bench near the shop depressed, and a man came across her. The man introduce himself as Jin Sen Kai, and he asked her if she is a Magic World user or not. To which she said she is. Kai then offer to trade her Buddy Rare for his Buddy Rare as he revealed "Artificial Angel, Virginie Casta". She accepts the offer as the Buddy Police Tasuku Ryuenji arrives and give both a Core Deck Case. She then tries to "Luminize" it and it takes the form of a plain, oval blue gem, and it fits into her necklace.
She then spectate Kai's match against Tasuku Ryuenji and Kenta Zakoyama, and after that, she decided to challenge someone, she came across Kazane Fujimiya, who is also spectating the fight. And challenges Kazane, to which she lose after using all her defense up against the powerful assault power of Dungeon World.
After the fight, Tasuku, who is delighted in Sei'ei's skill, gave her 3 blank Impact Card like how he gave "Gargantua Punisher!!" and "Dragonic Punisher" to Kai. To which Sei'ei gratefully accepts. A phenomenon than cause one of her blank card to glows, and it turns out to become "Magical Punisher!!". She then adds it to her deck.
Buddy Police Registration Edit
A week after she got her buddy, the Buddy Police opened the "Buddy Police Youth" section, to honor the "Buddy Police Youth" during the fight against Yamigedo. Much to Sei'ei's happiness and excitement, she signed up for it. And she pass the test for it - She is now one of the buddy police, and is given a Neo Core Deck Case. Tasuku then visits her, asked for one of the blank card back so that it can be replaced with "Radiant Punisher!!" , much to Sei'ei's surprise as the card cannot be used by her, and a phenomenon then, again, blank the artwork of "Radiant Punisher!!" out.
Gaen Cup II Edit
After she heard about the Gaen Cup II, she decided to enter it. During the first round, she is put up against Genma Todoroki, but she ultimately wins using the all out assault.
In her room at home, a strange light glows from her buddy card, as it transform into a Star Dragon World card.
As the second round comes, she is put up against the evil Davide Yamazaki, who uses "Armorknight Deathgaze" to continually inflict Spectral Strike, to make it worse, it is paired with Danger World's extreme battle power. The worst part is, it is abusing the use of Star Dragon World's high soulguard. However, Sei'ei managed to survive and wins using her buddy's new power.
Magic World Edit
Sei'ei uses a Magic World deck focusing on the <<Wizard>>. After her fight with Tasuku Ryuenji, she is given 3 Blank Cards. One of them was made into "Magical Punisher!!", which lets her to deal 3 damage, and add one of its additional effect.
"Endless magic, Transcend the past and future! Luminize! Transcendence Magic!".
Star Dragon World Edit
She later uses Star Dragon World deck focusing on her buddy's evolution - "Future Starlight, Virgini Casta". And incorporates "Radiant Punisher!!" to top it up.
"Magical Stars, shine brilliantly and transcend the reality! Luminize! Star Transcendence Magic!"