Both have zombies as well as the common theme of being stuck in a building during the outbreak as they wait for authorities to step in and save them.
Both are set in an apocalyptic world and have great characters with emotional energy between them. A lot of interesting alliances and relationships formed in the face of terror.
Both have the slice of life element and a nostalgic feel to it. It is slow paced and has well written characters with beautiful osts and a satisfying cinematography. The enjoyable plot and flow of the story along with the good acting makes the cherry on top.