Spurred by the flame raging in his heart, the Black Swordsman Guts continues his seemingly endless quest for revenge. Standing in his path are heinous outlaws, delusional evil spirits, and a devout child of god. Even as it chips away at his life, Guts continues to fight his enemies, who wield repulsive and inhumane power, with nary but his body and sword—his strength as a human.

Meet Sasaki, an overworked, middle-aged office worker. His days are marked only by the passing of more unrewarding corporate drudgery. Smoking helps take the edge off, but other than that, the only bright spot of his day is when he goes to the nearby supermarket and sees Yamada's smiling face. So, one evening after yet another exhausting day, he heads to the supermarket to find he missed Yamada's shift. Dejected, he decides to go find a smoking area but discovers there isn’t one to be found. Just as he’s about to leave, a girl in a biker jacket named Tayama asks him to join her at a secret smoking area!

University is back in session for Iori, and so are the booze-fueled parties! Between diving club shenanigans, a surprise from his sister, and wild tests of courage, normal college life is anything but. Dive back into the madness with Iori and his beloved crew of lively splash artists.

A warrior from a post-apocalyptic future travels to 1997 to protect an AI scientist being hunted by an unfeeling — and indestructible — cyborg.

Iori Kitahara moves to the coastal town of Izu for his freshman year at its university, taking residence above Grand Blue, his uncle's scuba diving shop. Iori has high hopes and dreams about having the ideal college experience, but when he enters the shop he is sucked into the alcoholic activities of the carefree members of the Diving Club who frequent the place. Persuaded by upperclassmen Shinji Tokita and Ryuujirou Kotobuki, Iori reluctantly joins their bizarre party. His cousin Chisa Kotegawa later walks in and catches him in the act, earning Iori her utter disdain.

Based on Kenji Inoue and Kimitake Yoshioka's popular comedy manga, Grand Blue follows Iori's misadventures with his eccentric new friends as he strives to realize his ideal college dream, while also learning how to scuba dive.