Emilia and Ram's Very Bumpy Master-Servant Relationship (エミリアとラムの主従凸凹) is a shop exclusive limited edition short story. This was later adapted and included in the Re:Zero Ootsuka Shinichirou Art Works Re:BOX.
Ram finds Emilia trying to sing with a bucket over her head in the silent of the night much to Ram's confusion. Emilia then goes on telling Ram to remember what had happened at the most recent meal they've had, with Ram saying "ah your attempt to sing that looked like birds were being brutally murdered? I remember". Emilia sadly admits that she needs a bit of improvement when singing, so she mentions that she is using the bucket in her head to hear her own song better and notice where she is failing(as per suggestion of Subaru). Ram not taking Emilia seriously at first and annoyed by her ingenuity, later remembers that these characteristics reminds her of Rem and offers to help Emilia until she gets better. Later that night Ram says that Emilia's singing improved a bit, deserving a 9. Emilia with sparkly eyes asked "9 out of 10?", with Ram replying "9 out of a 100 and your previous attempt was not worthy to be rated as music since it was really bad", reguardless Ram said she would keep her word and attempt to help Emilia as a teacher night after night in this very long road of learning how to sing.