|Japanese Name||双樹 あやせ・ルカ|
|Weapon||Sword (Ayase), fireballs (Luca)|
"Since we've become so close, I'll show you something cool!"
— Ayase Souju, chapter 7.
"It's the beauty of life! I'm sure you already understand!"
— Luca Souju, chapter 8.
Souju (双樹 Sōju) is an antagonist appearing in Puella Magi Kazumi Magica. She is a magical girl with a split personality, having two different identities named Ayase (あやせ Ayase) and Luca (ルカ Ruka), each with their own soul gems, outfits and powers.
Souju is a traveling magical girl who collects soul gems from her opponents. Her current targets are the Pleiades Saints.
Ayase acts cheerful and innocent, but only to drop her enemies' guard before letting loose her more vicious side. She is obsessed with collecting new soul gems, particularly the brighter ones of powerful magical girls.
Luca is more calm and reserved, though she is just as vicious as Ayase and seems to enjoy the challenge of collecting soul gems as well.
Both Ayase and Luca are very protective of each other's soul gems.
Ayase and Luca have so far only appeared in Kazumi Magica.
Instead of fighting over witch-hunting territory, Ayase wanders the countryside in search of new soul gems for her collection. She was en route to Mitakihara City, but decided to stop by Asunaro City after hearing about the Pleiades Saints. It's revealed that she was directed there by Kanna Hijiri.
Ayase made her debut in Chapter 7. She followed Kaoru, Saki, Satomi, and Mirai across the city and witnessed them taking a girl's soul gem for an as-of-yet unknown purpose. This, coupled with the brightness of their soul gems, made her determined to claim them for her collection. The next day, she follows Niko, Kazumi and Jubey to Asunaro's amusement park, La Vie Land. After introducing herself and showing off her gems, she taunts Niko for also having engaged in "picking gems". This leads to a battle between the two.
Eventually, Ayase is cornered by Niko's clones and has her soul gem removed. Niko thinks she has defeated Ayase, but is caught by surprise when Luca awakens in her place and attacks. Luca reclaims Ayase's soul gem at the end of the chapter.
Luca asks for Kazumi's name, threatening to take her soul gem. Jubey then claims that girls who lose their soul gems lose their magic and can even die (which is true, in a sense). Kazumi attacks Luca, but Luca uses "Cazzo Freddo" to freeze her. She notices the rarity of Kazumi's soul gem (her earring bell) not being located on her body, and tries to get a hold of it. Kazumi tells her not to touch it, suddenly unfreezing herself and hitting Luca in her soul gem. Luca then uses both her soul gems to be Ayase and Luca at the same time. Kazumi fires at her with Limiti Esterni while Souju uses a new attack named "Picchi Gemellati". The Soujus' attack makes it through and hits Kazumi, sending her flying. Watching the battle from afar, Niko receives a telepathic message from Saki, checking if Niko has taken Souju's soul gem. Niko asks Jubey what "Picchi Gemellati" means, and he believes it means "Twin Peaks". After watching Souju's power, Niko picks up Kazumi and flees with her and Jubey inside a roller coaster.
Niko tells Kazumi that Souju's attack creates an explosion through their perfectly synchronized fire and ice magic. They are capable of this because they use the same body. Kazumi doesn't understand this, causing Niko to use tempura ice cream as a metaphor. Niko then claims that they have to do something similar with her own magic. This prompts Jubey to say that Kazumi's magic and Niko's reconstruction magic are like hot and cold. They encounter Souju again and all three of them fire. The Soujus' attack sends them flying, prompting Niko and Kazumi to try and combine their magic. Their magic hits Souju's own attack, but it fails to negate it. Niko and Kazumi flee again through an underground "staff only" tunnel, as Niko comments that the Soujus are better synchronized. When Souju comes across them, Kazumi and Niko are holding hands. The Soujus fire "Picchi Gemellati" again, but this time when Kazumi and Niko combine their magic Jubey bites their hands. This causes them to become synchronized, pushing their magic tight through Souju's and causing an explosion that sends them to the surface.
Kazumi tells the Soujus that they've lost, but they respond by pulling out a box of evil nuts. They throw two of them at Niko and Kazumi, but Saki appears and catches them in mid-air. The other Pleiades jump down behind Kazumi, as Saki asks where the Soujus got the evil nuts. Souju laughs instead of answering and tells the Pleiades to kill them, calling them "magical girl hunters" (similar to a phrase said by Yuuri some chapters before). Kaoru says they aren't murderers, but because they can't let the Soujus go they're taking they're soul gems. Kaoru says that Souju's soul gems are at their limit and pulls out both their gems.
In an attempt to keep magical girls from becoming witches, the Pleiades take Ayase and Luca's soul gems, along with their body, to the Freezer, where they are to be kept in stasis until they can be purified. Niko kept them in with the soul gem and body of another magical girl. The bodies of the magical girls had been shrunken to the point where they can be picked up by one hand. Niko puts into the bodies into two new containers, saying they "will keep on waiting for the prince's kiss."
Later on, as Saki becomes a witch, Mirai uses her "La Bestia" attack to retrieve the Soujus' gems from the Freezer. Their corrupted soul gems simultaneously hatch into two grief seeds, giving birth to a giant witch with two faces. The Souju's witch then fights against Kaoru and Umika, protecting Saki's witch in the process.
Powers, Weapons and Abilities
While she wields a katana (a Japanese sword), Ayase mainly fights by shooting fireballs at her enemies using spells named "Avviso dell' Ustione" (meaning Burn Notice) and "Secondo Stagione" (Second Season). Because of her second Soul Gem, she can fight even after being incapacitated by switching to Luca's personality.
Likewise, Luca has a similar sword and can use ice magic with a spell called "Caso Freddo" (Cold Case). The pair can also combine and use a spell called Picchi Gemellati (Twin Peaks), in which their attacks must be in sync or otherwise they would cancel each other out. However, since they share one body, they are able to synchronize their attacks perfectly. This spell uses their opposing magic types, fire and ice (contraction and expansion), and causes an explosion.
- Ayase's debut draws several parallels to Kyoko Sakura. She spies on her future opponents with enchanted binoculars, wears similar casual clothing and has a similar hair-style.
- Ayase and Luca's outfits, soul gems and magic are all inversions of each other. While in egg form, their gems share the same two emblems with the locations swapped. While transformed, their gems on on opposite sides of their chests.
- Despite using fire magic, Ayase's color scheme is primarily white. Likewise, Luca uses ice magic but has a primarily red outfit.
- Ayase and Luca's attacks reference American television dramas Burn Notice, Cold Case, and Twin Peaks.
- Souju's last name means "twin trees".
- Ayase comments that the Pleiades have been taking soul gems that are dirtied. She has a fairly large soul gem collection, but apparently doesn't have to collect grief seeds and replenish them. From this, it can be assumed that soul gems stop accumulating darkness if they're separated from the owner, which may be why the Pleiades are taking soul gems from other magical girls (so they don't become witches). She may have Jubey clean them, although he doesn't seem to know her at first (but he may be hiding it as part of some larger scheme).
- Presumably, there is some sort of method that lets Ayase and Luca, but not any of their other soul gems, control the body.
- Some have come to believe that Walpurgisnacht and Ayase have things in common, such as the fact that if Ayase eventually collects enough soul gems, they might merge with her and she could become the ultimate magical girl. Walpurgisnacht is said to be a compilation of many magical girls turned into witches.