|Real Name||Seiru Astoria|
|Voice (Japanese)||Yui Horie|
|First Appearance||Ep 18|
|X-Rares||The ArcAngelia Isfiel (given to Clackey)|
Seiru Astoria is a character from Battle Spirits Shounen Gekiha Dan.
AppearanceSeiru has yellow hair, which she keeps hidden in a cap. She wears gray clothes as well.
Seiru cares very much about her brother, which is why she wanted to join the tournament.
Seiru and Keith were siblings. One day, they were playing Battle Spirits and Seiru decides to quit because she cannot beat Keith with her "weak cards". Keith comforts her, saying that her cards are not weak and rarity does not determine victory. He then gave her the ArcAngelia Isfiel card.
Brustom took over the kingdom, and with Keith leaving it Seiru was left to fend for her own.
Seiru wanted to enter the tournament, but she wants strong cards. She tries to steal Jin's cards.Dan, Clackey, Magisa and Zungurii arrive just in time to break up the fight. Later, she explains why she wants to enter the tournament. Clackey promises her that he'll bring her brother back.Clackey's next opponent is Lightspeed Shula, a card battler who can defeat opponents in one turn. Seiru immediately recognizes him as her brother. Clackey won the duel. Afterwards, Keith left for his own personal journey, and left a note and the ArcAngelia Isfiel (which was taken by Brustom) to Seiru. Seiru gave the card to Clackey, because he was the one who made her smile.
During the flashback, Seiru could be seen using a yellow deck. Here are the only known cards:
|18||Single Battle||Keith Astoria||Lose (Surrender)|