Beatrice and Rem's Cumbersome Delight is a shop exclusive limited edition short story. This was later adapted and included in the Re:Zero Ootsuka Shinichirou Art Works Re:BOX.
Beatrice is spooked by a person that has just entered the library with an angry look, said person checks the bookshelves, notices that they are still full of dust and then proceeds to scold Beatrice harshly for not being able to clean her own library properly. After a while Rem reveals that her true purpose in coming was not to check on the cleanliness of the library but to ask Beatrice for a favor. She wishes to create a dish, specially made for Subaru just as Ram and Emilia had done in the past, since last time she felt quite left out, and mentions that Beatrice has a similar taste to Subaru in food. Beatrice is unwilling to cooperate since, in the end, it would be something to please Subaru, though the smell of the food and Rem's persuasion makes her start tasting and rating every dish Rem presents to her.
Some days later, at the dinner table, Subaru is presented with the dishes that were approved and mentions that Beatrice seems to have gained a bit of weight recently for some reason. The story ends with a Rem happy with the results of her efforts (and unwilling to tell Subaru about Beatrice's help), a delighted Subaru and an angry, slightly fatter Beatrice.