Soubiwaku Zero no Saikyou Kenshi: Demo, Noroi no Soubi (Kawaii) nara 9999-ko Tsuke Houdai

In a world where your number of equipment slots—the number of soul contracts you can make with adventurer weapons and other such gear—determines your status, Noroa found himself with exactly zero slots.

Then one day, he found a mysterious doll who told him that he has the ability to equip 9999 pieces of equipment...but only if they're cursed! Starting with a cheatingly powerful cursed sword, Noroa's adventure begins!

(Source: Square Enix, translated)