Waccha PriMagi!

After the invading dimensional monsters were beaten back, Seoul was rebuilt. This is the story of Closers in New Seoul. Mysterious dimensional gates opened all over the planet and unleashed a worldwide invasion of dimensional monsters. No monsters and tactics had any effect on the waves of dimensional monsters pouring out of the dimensional gates. City after city was mercilessly destroyed. But the opening of the dimensional gates did not only cause damage and destruction. The psychokinetic power that it awoke also enabled a tiny minority of humans to gain extraordinary psychic powers. With these psychic warriors, governments around the world were able to turn the tide of the war with these monsters. After unspeakable losses, the people of earth at least succeeded in closing the gates. Since they had closed the gates, these psychics began to be called "CLOSERS," and the invasion of the dimensional monsters was named the First Dimensional War. With the dimensional monsters vanquished, peace returned to the world, and the cities were rebuilt. Through dedicated research into the dimensional gates and psychokinetic power, humans learned that the gates open when there is a singularity in this mysterious power. However, their understanding of the gates was still incomplete. The CLOSERS who survived the First Dimensional War became part of an organization called UNION. Together, they researched the psychokinetic power in all over the world, working to prevent another dimensional war. And that's when the dimensional gates all over the world started shaking again - as ever stronger outbreed creatures renewed the attack on earth. (Source: Wikipedia)

After inheriting the company from their parents, siblings Yuuhi and Yuamu Oudou have started to work at Ultraterrestrial Trouble Solutions, an organization that hunts aliens. Although they have never encountered aliens before, Yuuhi is desperate to meet one as he believes that an alien has stolen his important item called the "Earthdamar." One day, while searching for extraterrestrial creatures, Yuuhi and Yuamu find a strange spot in the forest where many trees have fallen, forming a scenery similar to a crop circle. As they venture further, they discover a mysterious spaceship and enter it out of curiosity. To their surprise, they come across Yudias Velgear, an alien from the Velgear Star Cluster. As it turns out, Yudias is seeking to learn about Rush Duel—a card game popular among elementary school students—as he believes that it will save his home from a long war. With the siblings agreeing to teach Yudias about Rush Duel, they eventually realize that their first contact with an alien may not be a random coincidence. [Written by MAL Rewrite]

High school student Yuuichi Katagiri cherishes his close circle of friends, composed of four classmates: Yutori Kokorogi, Shiho Sawaragi, Makoto Shibe, and Tenji Mikasa. However, when the funds for the upcoming school trip are stolen, the incident causes Shiho and Makoto—who had been tasked with collecting the money—to distance themselves from the rest of their class. Soon after, Yuuichi and his friends are deceived into meeting up and knocked unconscious by unknown assailants. After waking, the group find themselves confined in a white room with controversial figure Manabu-kun, who reveals that one of the five has gathered them together to clear their personal debt of twenty million yen. To pay off the amount, they must participate in a variety of psychological games that will test the true nature of their friendship and humanity. Distressed and isolated from the outside world, Yuuichi and his friends need to cooperate to complete the games. But as their concealed feelings and problematic pasts begin to surface, their seemingly unbreakable bond may soon shatter into irreparable pieces. [Written by MAL Rewrite]