The countdown to extinction begins on Sunday with the arrival of the Septentriones, otherworldly invaders set on the eradication of mankind. Caught in the crossfire, Hibiki Kuze and his friends join in the war for humanity's survival by signing contracts with demons to become "Devil Summoners." Soon, their abilities attract the attention of JP's, an underground agency led by Yamato Houtsuin. Once recruited into JP's, Hibiki and his friends fight and bond alongside other ordinary citizens who are Devil Summoners. However, with each new day, another Septentrione appears to wreak havoc upon Japan. Even if many lives are lost in the process, before that night ends, the young summoners must defeat the invaders at all costs. [Written by MAL Rewrite]

Junichirou Kagami is a young published physicist, a genius, and a hopeless otaku. At the mercy of YD, a self-diagnosed illness which causes him to only be able to do what he "Yearns to Do," Junichirou foregoes his scientific career to maintain and improve his anime blog. However, when he gets hired as a high school physics teacher; his sister Suzune, no longer willing to tolerate his NEET lifestyle, forces him to take the position. Despite the fact that Junichirou has no motivation to teach the standard curriculum, he may still have something of value to teach his students outside of academics. With his class in tow, Junichirou embarks on an unlikely journey filled with life lessons such as acceptance of others, how to make lasting friends, and what it means to live a better life by doing what you yearn to do. [Written by MAL Rewrite]

Hiroshi was ordered to be the manager of his company's Mexico branch in order to collect the fruit of a new type of cactus that has the sweetest nectar. So, Nohara family packs up and moves to Mexico to live there. They had to bid farewell to their acquaintances and the citizens of Kasukabe with tears. Shinnosuke heard that Mexican young girls are stylish and beautiful and became eager for this journey. On arriving at Mardequellyovaca city in Mexico, a new life full of anxiety, surrounded by unique neighbors awaits them. But Shinnosuke and Nohara family had no idea that flesh-eating killer cactuses are going to attack.

To save the town, the Nohara family and their neighbors work together to fight against "Killer Cactus". 

(Source: Wikipedia)

By finding a rare Action Kamen card, Shinnosuke Nohara and his family end up being chosen to go to a parallel world and help foil an alien invasion that is occurring over there. 

(Source: ANN)