One more fan character for "Bungou stray dogs".

Hikari is the daughter of Seich Matsumoto and Jin Iris Murdoch (these are Japanese and British authors, if that. Let the authors forgive me for this).
Her parents were killed and she turned to ADA. Dazai and Atsushi took over her case, and their investigation also led to the mafia. During the investigation, the girl became attached to many people, but her connection with Dazai was special. He saw in her something resembling Odasaka, and they understood each other. Hikari helped him get rid of regrets and stop thinking about death, and Dazai responded in kind, convincing her that she had something to live for. They did NOT have a romantic line. It was the story of a relationship between two deeply lonely and unhappy people. In the end, in order to avoid a war between ADA and the mafia, Hikari used her full ability to take away the pain of others (the memories remained, but the pain and emotions were released), but the side effect was that she lived it all herself. Feeling the pain of all those people, she failed and fell into a coma, but she achieved the result.