Btooom!

is a Japanese manga series written and illustrated by Junya Inoue. It has been serialized in Weekly Comic Bunch since 2009 and later in Monthly Comic Bunch, with chapters collected into 26 tankōbon volumes as of March 2018.

An anime adaptation covering the first 50 chapters of the manga was produced by Madhouse and aired in Japan on Tokyo MX from October 4 to December 20, 2012 and was streamed with English subtitles by Crunchyroll. The manga series was licensed for an English-language release in North America by Yen Press. The anime series has been licensed by Sentai Filmworks for an English-language release in North America.

In March 2016, an online mobile game for the Btooom! anime was announced. The game's name was later revealed as Btoom! Online and had its official release in Japan on 28 February 2017.

Plot
Sakamoto Ryōta is an unemployed 22-year-old who lives with his mother. In the real world, there may be nothing really special about him, but online, he's one of the world's top players of the combat game "BTOOOM"!

One day, he awakes in what appears to be a tropical island, though he has no memory of how or why he has come to be there. While wandering around, Ryōta sees someone and calls out for help. The stranger responds by throwing a bomb at him! Now Ryōta realizes both that his life is in danger and that he has somehow been trapped in a real-life version of his favorite game! Will Ryōta be able to survive long enough to figure out how and why he ended up here?

Official

 * Btooom!'s Official Website

Other Sources

 * Anime News Network (Manga)
 * Anime News Network (Anime)
 * Wikipedia