Reversing fate from the signing of the contract

There is a strange legend circulating in the endless world
Sign a contract with the store manager in a special small store, and you can get everything you want
strong power!
Countless wealth!
Knowledge of another world!
But few people know that this store also has the power to change fate
Whether past, present or future
or race or identity
When they are willing to risk everything to change their destiny
The doors to this store will be opened for them
A new destiny will also be born here!
"Sign a contract with me, and then——surpass fate!!"
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At the same time, Lan Xing, who is the store manager, is looking helplessly at the household budget book in his hands with an increasing deficit.
Because I don’t know when the girls in the store seem to be more and more
Twin ghost maids, an elf girl who likes dolls, and a cat-eared blade who turns into a sword...
'The meal fee has increased again this month. '
Obviously at first he just wanted to respond to a gentleman's kindness...
(Also known as Dimensional Aid Exchange, Dimensional Master House, Dimensional Exchange...)