Ordinary High-School Student Arata Kasuga wakes up one day and finds a mysterious black sun burning in the sky. No one seems to find it odd... and soon it becomes apparent that something is wrong.It turns out that this world was an illusion created by Astil Manuscript, a Grimoire that his Childhood Friend and cousin Hijiri left behind when the Black Sun caused the "Breakdown Phenomenon", destroying his hometown and all his friends. However, he discovers that Hijiri is still alive, and together with Lilith Azami, a girl who facilitated his discovery of The Masquerade, he decides to become a Magus in order to save her.To this end he joins a Wizarding School where Lilith works as a teacher (despite her youth), where the headmaster is a Chivalrous Pervert, and where he meets "Trinity Seven" — a school body composed of seven of its most powerful mages, of which Lilith is one. Thus Arata begins his quest to control the grimoire Hijiri bequeathed to him in order to save not only her but his entire hometown, unaware of what lies ahead.Trinity Seven: Shichi-nin no Mahou-Tsukai is an ongoing 2010 manga series by Kenji Saitou, with illustrations by Akinari Nao. A drama CD was also released in September 2011. An anime adaptation is scheduled for October 2014.
Balanced Harem: Mostly. Lilth is Arata's favorite, but he shows a fair share of attention to all the girls, and the manga seems to be aiming for a Harem Ending (which is apparently how Trinity Seven is supposed to work).
Bare Your Midriff: Akio tends to only have the top few buttons of her shirt done up, leaving her belly exposed.
Big Brother Instinct: Arata carries around a picture of himself and Hijiri that she drew as a child. He's immediately accused of having a sister complex because of it.
Buxom Is Better: Arata seems to think so. Though smaller ones have their own charm too.
Chekhov M.I.A.: It's mentioned early on that the seventh of the Trinity Seven went missing a year or two ago. That's Liese.
Chekhov's Gun: A drawing by Hijiri during her childhood clued in Arata to The Masquerade — the sun is red, not black as most people in his "reconstructed" hometown think.
Chekhov's Skill: Arata's Nudifier anti-magic attack turns out to be essential to his power copying, as using his power to deconstruct another's magic is the required last step of learning to access that mage's Archive and Thema. Yep, his power mandates indulging his perversion.
Chivalrous Pervert: Arata will gladly comment about how hot Yui is despite her childlike appearance, but he wouldn't kiss her. Yet.
Clingy Jealous Girl: Some members of the Trinity Seven start to get jealous when a girl gets closer to Arata.
Henshin Hero: Use of magic requires entering Magus Mode, which involves opening one's Grimoire, an Instant Costume Change into a (cooler or sexier) outfit, and conjuring any required tools. (Lilith, for example, goes from her more conservative preferred clothes to A-grade Zettai Ryouiki, a tight white sleeveless blouse and short tie, and full-length Opera Gloves, plus BFG.) Leaving Magus Mode returns one's clothing to normal — unless one has been forcibly returned to normal by Arata's Anti-Magic, of course.
Improbably Female Cast: Justified by way of Mother Nature, Father Science. Characters explain magic as a very emotional practice but men tend to the more theoretical side of things. So, there are more female mages than male. The only male mages seen so far are Arata and the Headmaster, as well as a few nameless (and outnumbered) background characters.
Also, Magic Kings are apparently universally male, though candidates can be either sex.
In the Name of the Moon: The Trinity and Arata's transformations begin with this: "Connecting to the [insert name] Archive, executing my thema".
Just Friends: Even with the romantic implications, Arata would prefer he and Lilith's relationship stay this way.
Kick Chick: Akio's primary means of magic delivery is via devastating kick.
Personality Powers: Played with. Magic operates irrationally and without "common sense", so a regular mage can only use it by working with a thema that is absent from his/her normal personality makeup, subverting it for regular mages. Evil Mages, meanwhile, seem to give in to the nature of their thema and archive for power, playing the trope straight.
Potty Emergency: Exaggerated into fourth-wall breakage in chapter 3. Arata, Lilith, Levi, and Serina are trapped in a barrier around his dorm room, and one of them observes they'll have to get out eventually just because there's no bathroom there. Cue Lilith suddenly having to go, then Levi, then Levi faux-hypnotizing Serina into needing to go, all while they crack jokes about the direction the manga is taking so early, or Serina blaming Levi for wanting them all to become "piss heroines."
It's implied every Last Crest involves the user taking massive risks for similarly massive power. More than a few mages choose to broaden their power base by exploring other Themas rather than seek out something so dangerous, even if they could potentially achieve the power to become one of the Trinity Seven.
Power Incontinence: The Breakdown Phenomenon can be invoked willingly, but more commonly seems to be caused by very poorly controlled phenomenal magic power. Arata can cause it (or make an existing situation worse) if he loses control of his powers, and a similar thing happened with Yui. The Grimoire Security organization that Mira and Akio work for is dedicated to shutting down occurrences of the Phenomenon by any means necessary.
Power Perversion Potential: When Arata discusses learning how to focus his Anti-Magic attack to hit single targets, the others (not unreasonably) assume it's because he wants to be able to disrobe them more effectively.
Reality Warper: The potential heights of Arata's power, given the reconstruction of his hometown at his wish in the first chapter.
Refuge in Audacity: Arata lives by this. Every time he's found in a compromising situation, he pushes it further so he can get away with nearly anything being "just a joke." Magic works better for him as a result of thinking like this, too.
Refusal of the Call: When first offered power during the Breakdown Phenomenon, Arata wished for nothing more than his normal life and cousin back.
Rule of Three: Threes are important in magic - "Trinity" keeps popping up for a reason. Mages can learn more than one Thema within their Archive, and those who have learned at least three are able to access some kind of "trinity" mode or power. It's also the prerequisite to controlling some of the most powerful magic weapons, and seems to be inherent in mastering one's own Magic King potential. Oddly, the Trinity Seven are themselves not quite bound by the same rule to get that title; instead they have to master the Last Crest ultimate magic of their Archive.
Title Drop: The Trinity Seven are a set of seven powerful magi who have learned the Dangerous Forbidden Technique at the heart of each of their magic Archives, one for each type. All the current group are students at Royal Biblia Academy. They are ostensibly the most powerful mages in the world after an awakened Magic King, though so far the current Seven have been hit by The Worf Effect a few times, especially against the evil mages of Ish Kerioth.
Token Mini-Moe: Yui is an unusual example, being a large breasted little girl.