Forgotten title!!! I want to reread this novel
The story follows the MC, who initially transmigrates into a game-like world where he levels up with the help of a system. However, after completing his "task," instead of returning to his original world, he ends up in a primitive, beastmen-like world with his system still functioning. The system grants him gold bars as currency, and he obsessively counts them every night.
The ML, a strong and protective member of the tribe, saves the MC and brings him back to his tribe. Initially placed in a communal cave, the ML later gives the MC a private cave near his own. The MC's modern knowledge and system capabilities make him stand out in this primitive world, and his relationship with the ML grows steadily.