Jigoku Shoujo (2006)

Both about a death girl who will help with revenge in exchange for the persons soul.

Similar theme about people that have made a pact/are approaching their own demise. The story about the Death Girl.

Both dramas are centered around female character who makes a revenge on bad people.

Jigoku Shoujo is more magic/mystery based while Girl from Nowhere is more psychological.

Synopsis
Have you heard of Hell Correspondence? Those with a powerful grudge may only access this mysterious website at midnight, allowing them to enter anyone's name and have that person be ferried straight to hell. Ai Enma, the Hell Girl, will not judge whether or not the chosen target deserves punishment; she will merely exact revenge on them for you. Not much is known about this young girl other than that she swiftly carries out her tasks with the help of three straw dolls. There is just one catch, however—as payment for carrying out such a request, the user must condemn themselves to an afterlife in hell.

Written by MAL

Have you heard of Hell Correspondence? Those with a powerful grudge may only access this mysterious website at midnight, allowing them to enter anyone's name and have that person be ferried straight to hell. Ai Enma, the Hell Girl, will not judge whether or not the chosen target deserves punishment; she will merely exact revenge on them for you. Not much is known about this young girl other than that she swiftly carries out her tasks with the help of three straw dolls. There is just one catch, however—as payment for carrying out such a request, the user must condemn themselves to an afterlife in hell.
Source :MAL

Both are about an "revenge agency" of sorts, where a customer can make a deal to have revenge taken on someone who wronged them. One has more fantasy elements and comes with more consequences, but the topic is similar and both are episodic.

Both are very similar..................................................................
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Have you heard of Hell Correspondence? Those with a powerful grudge may only access this mysterious website at midnight, allowing them to enter anyone's name and have that person be ferried straight to hell. Ai Enma, the Hell Girl, will not judge whether or not the chosen target deserves punishment; she will merely exact revenge on them for you. Not much is known about this young girl other than that she swiftly carries out her tasks with the help of three straw dolls. There is just one catch, however—as payment for carrying out such a request, the user must condemn themselves to an afterlife in hell.

Written by MAL

Have you heard of Hell Correspondence? Those with a powerful grudge may only access this mysterious website at midnight, allowing them to enter anyone's name and have that person be ferried straight to hell. Ai Enma, the Hell Girl, will not judge whether or not the chosen target deserves punishment; she will merely exact revenge on them for you. Not much is known about this young girl other than that she swiftly carries out her tasks with the help of three straw dolls. There is just one catch, however—as payment for carrying out such a request, the user must condemn themselves to an afterlife in hell.

Written by MAL

Both are based on famous horror manga. Both are very similar........................................................................

Both are based on famous horror manga. Both are very similar.................................................... ..