Season 1
The story takes place at Koryo Academy, a high school where students manifest a personal weapon called a Blaze, which is a physical manifestation of their soul. The protagonist, Tooru Kokonoe (sometimes “Tor”), enrolls in the academy driven by tragedy: his younger sister was killed, and he wants to gain power to protect others and possibly avenge her. On entering, Tooru discovers that his Blaze is not a typical weapon — instead of a sword, lance or gun like many classmates, his Blaze takes the form of a shield, making him an “Irregular”. Koryo Academy uses a system called Duo — every student is paired with a partner (their “Duo”), who they train, live, and fight together with. Tooru is paired with Julie Sigtuna, a silver‑haired girl from Scandinavia and a very capable fighter.
Blaze
It is Tooru Kokonoe's first day and he attends the entrance ceremony for Kouryou Academy where all the students have to demonstrate their capabilities with their Blaze weapons.
Duo
Tor and Julie settle in as roommates until the time comes to form official Duos. Each has an ideal partner in mind, but will they get what they want?
Avenger
Tor and Julie face an unexpected hurdle at the end of their mock-battle tournament. Julie confronts Tor about someone from his past.
Exception
Transfer student Lilith Bristol joins Tor's class and immediately flaunts her status as an Exception. Tor and Julie go into town for some shopping.
Level Up
The Rite of Sublimation has given Tor and his friends upgraded powers. Lilith has another proposal for Tor ahead of a challenging inter-class battle.
Survive
Lilith ropes her fellow students into fighting her in a battle royale. A mysterious figure shows up out of nowhere with his own plans for Lilith.
Silver-Blonde, Yellow Topaz
The class is off to a seaside summer camp, but this is Koryo Academy. No ordinary school function is complete without some kind of combat.
Selection
A week of training is capped off by a day at leisure--and where better to unwind than at the beach? Miyabi takes a big step in her feelings about Tor.
Rebels
Koryo Academy is under attack! Tor and Julie work together in battling the chief of the marauding corps, while Tomoe searches for a missing Miyabi.
Reign Conference
Miyabi is still MIA as Koryo Academy prepares to host the mysterious Reign group. Tor presses Lilith for answers about Absolute Duo.
Killing Game
Tor and his friends confront the Rebels in Smith's grand killing game. Tomoe realizes she knows little about her Duo. K challenges Tor to a rematch.
Absolute Duo
The idea of wanting to protect someone is still foreign to K, so in a dramatic, no-holds-barred faceoff, Tor decides to show him how it's done.