re:zero kara kasaneru isekai seikatsu

A Re:Zero Kara Hajimeru Isekai Seikatsu side story published on April Fools of 2016, commonly known as Kasaneru or Greed IF.

Natsuki Subaru accepts Echidna's help and forms a contract with her. The actual chapter starts some time after the fifth arc.

This tag implicates re:zero_kara_hajimeru_isekai_seikatsu (learn more).