Reversing Fate from the Signing of a Contract

In the endless world, a strange legend circulates: in a special little shop, by signing a contract with the shopkeeper, one can obtain everything they desire—powerful strength, countless riches, and knowledge from another world! But few know that this shop also possesses the power to change destiny, whether past, present, or future, or regardless of race or identity. When they are willing to gamble everything to change their fate, the door to this shop will open for them, and a new destiny will be born here! "Sign a contract with me, and then—transcend destiny!!" — Meanwhile, the shopkeeper, Lan Xing, is looking helplessly at his ever-growing deficit in his account book. He doesn't know when it started, but the number of girls in the shop seems to be increasing: twin oni maids, an elf girl who loves dolls, a cat-eared blade that transforms into a sword… 'The meal expenses have gone up again this month.' He only initially wanted to reciprocate a gentleman's kindness… (Also known as the Dimensional Aid Exchange, Dimensional Oddity Store, Dimensional Exchange…)