Abruptly catapulted into a fantasy world, Mimori Touka and his classmates have been summoned by the world’s resident goddess to serve as heroes. Luckily, most of the students display amazing skills upon arrival—except for Mimori, whose abilities bottom out at a measly E-rank. With no further use for him, the goddess banishes Mimori to a dungeon from which no one has ever returned alive. Yet, as it turns out, Mimori’s skills aren’t so much worthless as they are abnormal. Abnormally powerful, even. If Mimori can only claw his way back to the surface, nothing will stand in his way from getting revenge.

After five years of harboring unspoken feelings, high-schooler Taiju Ooki is finally ready to confess his love to Yuzuriha Ogawa. Just when Taiju begins his confession however, a blinding green light strikes the Earth and petrifies mankind around the world—turning every single human into stone. Several millennia later, Taiju awakens to find the modern world completely nonexistent, as nature has flourished in the years humanity stood still. Among a stone world of statues, Taiju encounters one other living human: his science-loving friend Senkuu, who has been active for a few months. Taiju learns that Senkuu has developed a grand scheme—to launch the complete revival of civilization with science. Taiju's brawn and Senkuu's brains combine to forge a formidable partnership, and they soon uncover a method to revive those petrified. However, Senkuu's master plan is threatened when his ideologies are challenged by those who awaken. All the while, the reason for mankind's petrification remains unknown. [Written by MAL Rewrite]

On the 20th floor of the Tower, the "Regulars" who have been permitted to enter have to undertake arduous and extremely expensive tests to rank up. Most abandon hope and choose to stay where they are—but not Ja Wangnan. Wangnan is determined to reach the top and become the king of the Tower. However, he is weak and has repeatedly failed the exam, with debt collectors tailing him. In desperation, he attempts the exam one more time, only to encounter a mysterious and powerful individual: Jyu Viole Grace, a member of the crime syndicate FUG. Cursing his rotten luck, Wangnan has no choice but to form alliances with strong people, including Viole—who still refuses to be part of any team. Amid a dire situation, Wangnan must find a way to change Viole's mind to finally advance past the 20th floor, or he will never get a chance to build his legacy.

Third season of Kaguya-sama wa Kokurasetai: Tensai-tachi no Renai Zunousen.