Cube Arts Vol. 2 (manga)
MINE OR DIE!
Takuto, trapped in a sandbox-style video game, must save his friend Noa from slavery. So he crafts the Iron Greatsword, a powerful weapon made of diamonds. Meanwhile, the truth behind the Soul Stones that drop when a player is killed begins to emerge. Minecarts, monsters, mayhem...in this cubed world, the possibilities for fun--and death--are endless!