The episode focuses on the children's book Chavvot , which mirrors Chiyuki's lost memories.
"Episode 10 felt like the calm before a very heavy storm. After weeks of mystery, we finally learn the black-haired woman’s name is . The way her memories are tied into the storybook Chavvot is both beautiful and devastating. It’s becoming clear that she isn’t just a guest; she’s the key to Decim's growth as an arbiter. Death Parade Episode 10
The black-haired woman's name is revealed to be Chiyuki . The episode focuses on the children's book Chavvot