Pocket Princess: Game Tomodachi ga Isekai no Hime Datta kara Maou ni naru Koto ni Shita

Former professional gamer Himemori Aoi gets a one-way ticket to another world to meet his gaming friend Bell. "I'll become the Demon King." Aoi uses the "strongest weapon" created by Bell to fight against demons, beastmen, and the only reincarnated hero from Earth. A heart-pounding heroic battle fantasy!

(Source: Zebrack Comic, translated)