Fans often note the artwork is faithful to the version 1.0 (v10) character designs found in the game.
After reverse-engineering the viral TikTok videos, the "V10" refers to a pillowcase with these 10 features: 30+days+life+with+my+sister+v10+pillowcase+link
Within certain versions of the game (like v10), there are often hidden items or "easter eggs" that players can unlock. The "pillowcase" may refer to a specific CG (computer graphic) or an item within the game's narrative that players share links or guides to find. Merchandise: Fans often note the artwork is faithful to the version 1