Shangri-La Frontier 12

A fast-paced, irreverent adventure for fans of isekai and RPGs! High schooler Rakuro loves hunting down "trash games," but one day he decides to play a AAA VR game called Shangri-La Frontier instead. He creates a character with a bird head, skips the cutscenes and jumps right in--but what awaits him in this game is different from anything he's ever faced...
UPSIDE DOWN UNDER THE SEA
While looking to gather information about Ctarnidd, Sunraku unintentionally gets thrown into a bonus scenario that seems lethally dangerous. Alone in an undersea city full of vicious enemies and separated from his party, Sunraku has 170 hours to clear the scenario. Fortunately, Sunraku meets Araba, a friendly npc. Araba helps Sunraku get a better understanding of the environment and together they begin the search for Sunraku's friends. However, time is limited and Sunraku must honor his promise with Katzo to fight in the GGC. Logging off to go fight in a pro gaming competition might be what ultimately ruins Sunraku's chances of clearing the scenario, but with his party members holding the fort, perhaps there's a chance...

First released as a web novel in Japan, Shangri-La Frontier is author Katarina's manga debut.
Manga artist Ryosuke Fuji is best known for working on the Attack on Titan spinoff, Attack on Titan: Lost Girls, with both volumes published in English by Kodansha.