Unreal: Fujori Zakka Ten

Mysterious shop where the salesperson knows the customer's names.
The gifts/items cause harm to the person that receives/uses it including leading to death of the individual.

A mysterious shop granting wishes and desires..... probably at the extend of exchanging lives.

*Spoiler*

While Unreal is about two high school bestfriends and TStHF is abou two 'past' lovers, the ways they are separate due to some circumstances and how one of them, in order to save the other one make an exchange/deals with a mysterious shop owner..... unknowingly becoming neverending deals that they need to overcome.

-Both have supernatural elements
-In both there are demons and supernatural creatures
-Both are set in a misterious shop
-In both there are time loops and a festival repeating multiples times
-In both a boy sacrifices somenthing for his best friend
-Both have bromance elements, leaning to BL
-The ending is quite similar

-Both have supernatural elements
-In both there are demons
-In both there are time loops
-Bith are about two people connected and fated to die
-"Love thunder" is BL while "Unreal" is a bromance, more focused on their feelings rather than phisical affection