It’s just one more day of your adventures on another world when you suddenly find a curious object: a small, square piece of light blue metal with a big, red button on top. Dare you push it?
When you do, you find yourself on the sports field of what looks like a typical Japanese high school. It all feels familiar, yet strange at the same time. Is this what they call déjà vu?
From across the field, a strange, mustached man in a military uniform tells you it’s time for class to begin.
“Class…? What’s going on?”
Arriving at the classroom, you find others already sitting inside. It’s as motley a collection of characters as you’ve ever seen, as though they’re all from completely different worlds. They all return your curious gaze.
You quietly sit at a desk.
Moments later, a suspicious man with a white face dressed in a garish purple suit comes into the room.
“Good mooorning, claaaaass”, he yodels. “Let’s begiiiiiin.”
Isekai Quartet (異世界かるてっと, Isekai Karutetto) is a slice-of-life anime serving as a humorous crossover for the characters of four isekai light novel franchises published by subsidiaries of Kadokawa Future Publishing: KonoSuba: God’s Blessing on this Wonderful World!, Overlord, Re:Zero – Starting Life in Another World and Youjo Senki: The Saga of Tanya the Evil. In the anime’s second season, the cast is joined by the heroes of two more franchises: The Rising of the Shield Hero and Cautious Hero: The Hero Is Overpowered but Overly Cautious.
The story mostly takes place at what appears to be a high school in the suburbs of a modern-day Japanese city. Characters from various isekai franchises are placed in the roles of students, teachers and other school staff. While everyone retains their experiences and abilities from their native storylines, no harm or violence of any sort is permitted in this strange new world.
The otherwise ordinary school life takes a fantastical turn with the wide, colorful cast. Across franchises, the characters learn about and befriend each other in their own ways.
The main characters of KonoSuba, Overlord, Re:Zero and Youjo Senki make up Class 2 of the school and more about them can be found on other posts of my blog. Below are more characters from each of the four main isekai franchises who also appear in Isekai Quartet.
Characters from KonoSuba
Eris, a goddess of fortune (luck and wealth). Kind, gentle and responsible, she cares deeply about the welfare of others, particularly her worshippers, the Eris Order (Darkness is a member). In the heavenly hierarchy, Eris is Aqua’s subordinate. She is deeply insecure about her small bust size, which Aqua often picks on her for. Eris sometimes visits the Fantasy World in secret as Chris, an adventurer and a thief who taught Kazuma the Steal skill. In this mortal form, she has no access to her divine abilities, unlike Aqua. In Isekai Quartet, Chris is a student in Class 1.
Vanir, an arch-devil, a duke of Hell and a former general of the Demon King’s army. A shameless, boastful egotist, he enjoys (and feeds on) the embarrassment and disappointment of others. He also enjoys chaos and destruction. Despite this, Vanir always keeps his promises and never causes any lasting harm. He is believed to be even more powerful than the Demon King himself. Vanir’s true form is actually the domino mask he wears and, through this, he can either create his own body out of dirt or possess anyone who wears it. The mask is capable of reconstructing itself if it is destroyed. After he was defeated by Kazuma’s party, Vanir abandons the Demon King, hides in the city of Axel and sets himself up as an entrepreneur of sorts. In Isekai Quartet, he is a teacher.
Characters from Overlord
Sebas Tian, the dragonoid head butler of Nazarick and the leader of the Pleiades, a team of six maids highly skilled in combat. Steadfast and dignified, Sebas is a strong believer in justice and, unlike many of the Nazarick denizens, does not despise humans. He believes that humans are capable of both good and evil, but he won’t hesitate to kill any he deems irredeemably evil. He is a master of unarmed combat, able to defeat his opponents in the blink of an eye. In Isekai Quartet, Sebas is a school groundskeeper while the Pleiades are students in Class 1.
Hamsuke, a sentient, giant hamster. Ditzy and somewhat simple-minded, she was once known as the “Wise King of the Forest” in the Great Forest of Tob until she was subdued by Ainz, to whom she has sworn her loyalty. She has a long, scaly tail that she can use like a whip and has learned a few combat skills. In Isekai Quartet, Hamsuke is one of the school’s pets.
Characters from Re:Zero
Felt, a 15-year old professional thief and a candidate to become the 42nd ruler of the Kingdom of Lugnica. Feisty, street-smart and fiercely independent, she has lived almost all her life in Lugnica’s slums. Felt was the thief who stole Emilia’s insignia at the story’s beginning. After she was somehow chosen as a royal candidate, Felt loudly declared her hatred of nobles and vowed to dismantle them. In Isekai Quartet, she is a student in Class 1.
Roswaal L. Mathers, a mysterious Lugnican nobleman, Emilia’s patron and the employer of Rem, Ram and Beatrice. Eccentric, courteous and reserved, he is a cunning politician able to read others’ intentions well. Unlike most nobles, Roswaal has no prejudice against demi-humans. He is also a powerful mage proficient in the use of all six elements (Air, Earth, Fire, Water, Yang, Yin). Roswaal has an odd habit of yodeling when speaking. In reality, he is secretly Roswaal A. Mathers, an ancestor of the Mathers family who has possessed his descendants for generations in order to survive to the present day. In Isekai Quartet, Roswaal is the homeroom teacher of Class 2.
Characters from Youjo Senki
Erich von Rerugen, an Imperial Army Colonel and an officer in Strategic Operations, a division of the Imperial General Staff Office. Considerate, dutiful and observant, Rerugen is a talented military officer with intricate knowledge about the Imperial military and its logistics. He first met Tanya at the Officer Candidate School, where he stopped her from viciously beating a young trainee who had willfully disobeyed her. Since that incident, and after observing her career since then, he has come to see Tanya as a monster in a little girl’s body. Despite this, he has grown to trust and respect Tanya as a soldier, believing that only a monster like her can succeed and survive in the madness of war. In Isekai Quartet, Rerugen is a teacher.
Kurt von Rudersdorf, an Imperial Army Major General and Deputy Chief of Operations. Calm and decisive, he is a clever officer who is unafraid to take high risks if the rewards are worth it. He and Zettour have been close friends since their days together at the War College and he sees Tanya as a reliable, yet visionary leader. In Isekai Quartet, Rudersdorf is the school’s principal.
Hans von Zettour, an Imperial Army Major General and Deputy Chief of Logistics. Serious and thoughtful, he is a loyal officer who uses his thorough understanding about the Imperial military to assess the risks of military operations. Like Tanya, Zettour believes in rationalism and dislikes idealism. He is completely fascinated with Tanya’s revolutionary (modern-day) theories about war and how they could benefit the Empire. In Isekai Quartet, Zettour is the school’s vice-principal.
For those familiar with the original four isekai franchises, Isekai Quartet can be fun and exciting to watch. In fact, it’s one of my personal favorites.
It’s fun and heartening to see the various characters relate to each other, revealing more about themselves as people in casual situations their own stories do not have. A noteworthy example of this is Ainz and Tanya’s bonding over their common pasts as salarymen. It’s the first time both of them reveal their pasts to anyone. Without the stress of war and being watched over by a selfish deity, Tanya becomes considerably gentler and makes the friends she could never have in her old life. She also finally gets to have modern-day food and coffee again. Distanced from the poisonous influence of the Nazarick NPCs, Ainz gradually rediscovers the human within him by making friends with others.
While normally cold and abrasive, Beatrice has grown comfortable with Mare over their shared interest in reading. The devil Demiurge has found a kindred soul in Tanya, who shares his belief in control and order. For the first time, Emilia needs not worry about discrimination since there is no Witch of Envy in the world of Isekai Quartet. In many ways, the world of Isekai Quartet gives its inhabitants a happiness they could never have on their previous worlds.
Another heartening issue is the fact that two former shut-ins, Kazuma and Subaru, now have the opportunity to complete their high school educations. Surprisingly, this also applies to Ainz, who never graduated from middle school due to education being prohibitively expensive on his original world. While there would likely be no public recognition for this education, these people could gain new confidence through their learning.
Isekai Quartet is one of the most innovative ideas I’ve seen in Japanese anime. Not only is it fun to watch a good crossover, but it is also a way to keep viewers aware of the original isekai anime so that future seasons could be produced by Kadokawa.
Who makes the world interesting? We do!