Level 1 kara Hajimaru Shoukan Musou - Ore Dake Tsukaeru Ura Dungeon de Subete no Tenseisha o Bucchigiru (Webtoon)

Shinobu Ijima, a young man who died with his sister in a sudden explosion, is reincarnated into the world of Lavita Online, a game he played as a hobby. The only problem is, he’s back at level 1… When Shinobu finds out that his sister will also be reincarnated into his world, he begins a hellish training regime to gain the power to compete against max-level players. The WEBTOON version of the hugely popular original novel is finally here!!