A series of flashbacks shows that Namie Yagiri has a deep, obsessive love for her brother, Seiji . When Seiji became obsessed with a beautiful head in a jar found in their uncle's study, Namie moved it to Yagiri Pharmaceuticals to keep him away from it.

It is revealed that Mika Harima , who had been stalking Seiji, discovered the head in his apartment. In a fit of rage and obsession, Seiji killed her. Namie later had the head (supposedly) surgically attached to Mika’s body.

Fans have noted that in the light novel, Celty's head is described as having hair "as black as darkness," whereas the anime depicts it with brown hair.

In Durarara!! , Episode 9—titled —is a pivotal moment where the series begins to tie its many disparate plot threads together. Narrated by Namie Yagiri, it reveals the dark origins of the Yagiri family and the mysterious "head". Key Plot Points