After a mysterious death, King Grey is reborn as Arthur Leywin on the magical continent of Dicathen. Although he enters his second life as a baby, his previous wisdom remains. He begins to master magic and forge his own path as the years go by, seeking to correct the mistakes of his past life.

Sakura Kinomoto, an elementary school student who discovers that she possesses magical powers after accidentally freeing a set of magical cards from the book they had been sealed in for years. She is then tasked with retrieving those cards in order to avoid an unknown catastrophe from befalling the world.

Following the collapse of civilization, one storied hotel stands among the ruins of Tokyo’s Ginza district. Overrun by nature, this lone hotel continues to defy humanity’s collapse. Current guests: zero. Check-ins scheduled today: zero. Yesterday’s website traffic: zero. Enter with caution in this story of survival and mystery in a world where the memory of humanity begins to fade.

Iwatani Naofumi, a run-of-the-mill otaku, finds a book in the library that summons him to another world. He is tasked with joining the sword, spear, and bow as one of the Four Cardinal Heroes and fighting the Waves of Catastrophe as the Shield Hero. Excited by the prospect of a grand adventure, Naofumi sets off with his party. However, merely a few days later, he is betrayed and loses all his money, dignity, and respect. Unable to trust anyone anymore, he employs a slave named Raphtalia and takes on the Waves and the world. But will he really find a way to overturn this desperate situation?

Ryo is delighted to be reincarnated into the fantastical world of Phi, where he thinks he’ll get to live a quiet life learning to use his newfound water magic. Going with the flow here, however, means something very different. Ryo is immediately pitted against the wild lands he winds up in and the slew of deadly monsters that call the remote subcontinent home.

You’d think he’d forget about taking it easy when he’s stuck fighting for his life, but lucky for Ryo, he’s naturally optimistic, clever, and blessed with the hidden “Eternal Youth” trait. Twenty years pass in the blink of an eye, and each encounter along the way pushes him one step closer to the pinnacle of human magic. Little does he realize that’s only the opening chapter of his tale. A fateful meeting soon thrusts Ryo to the forefront of history, forever changing the course of his life...

Thus begins the adventures of the strongest water magician the world has ever seen—who also likes to do things at his own pace!