(This is for the fanfiction "Crossover Together". Info may change from canon information)
Seitenshi is the president of Tokyo, and the youngest president in japan.
Seitenshi is an extremely beautiful young female of pale skin and small frame. She is gifted with thin, white eyebrows and thick, superlative white eyelashes surrounding rounds eyes that encompass light irises. Her hair, which covers her forehead, leaving only several portions visible, is kept in messy standard; moving to the center of her face. A pack of hair falls directly to her small nose, in between her eyes. She possesses a small neck and thin lips, as well as ears that are hidden under her white hair.
True to her status, Seitenshi is dressed in a fancy white dress. The upper piece is designed with several objects donning swirling circles all over. On either side of her shoulders there are two ribbons and a thick emblem in the middle. The bottom of the dress, covering her thighs, displays an opening revealing partial portions of her legs, which are covered by white tights. The end piece of the dress is intricately shaped to resemble cherry blossoms. Seitenshi's head is covered by a white hat that has roses-like objects attached at the side.
Seitenshi is a rather serious individual at all times, and true to her status as president of Tokyo, takes many matters with full focus on. As she is put under much pressure, she does at times go in more paranoia matters in what could happen. She is the contrast to Victoria's more mischievous and laidback nature, whom she holds similar resemblance to Nagisa Shiota with his contrast to Karma Akabane.
During a TV broadcast in terms of Jizo and the houndours, Seitenshi explained to some of the reporters that they were deeply looking into it, but was not able to give any extensive information on the matter.
Seitenshi was invited to the royal ball in London England by The Queen, as predicted by Nagisa. During her stay, she ended up involved in the demonic activity, when she was almost killed alongside Victoria by Envy and Lust. She did survive the encounter, but immediately demanded to know what was going on for this to happen.
After the Pluton attack, she went to Amestris to discuss the matters at hand, saying that they can no longer try and cover it up any further. She asked how such a beast even came to their world, and after getting the answer in Sombra, confirmed that they had to stop him before he puts a stop to all of them.
On returning to Japan, she and Victoria took time to watch training of their soldiers, worried over the situation and believing that just one group of teenagers can't stop every attack. She got word on King Bradley's return, her trying to keep calm in spite of Victoria's teasing, and she tried to have them take things seriously. When Karma akabane arrived and began to tease King Bradley, she went as far as to slap him, saying he didn't need any of that.
As King Bradley was staying, Korosensei gave Seitenshi a hinted message to King Bradley's true identity, and she had him confronted to find out the answer, almost getting killed by Bradley in the process. This revealed Bradley's identity as a Homunculus.
Seitenshi appeared with the other leaders when they were informed about Sombra's past thanks to Kyoya Ootori. When Hiromi Shiota arrived, she helped in convincing her that what Nagisa had gone through was true. She was also present during the meeting before the final battle.