工作细胞

Meaning

Refers to "Double Black" - Dazai Osamu and Nakahara Chuuya. The most fearsome duo of the mafia who wiped out an enemy ability organization overnight. From manga "Bungo Stray Dogs" (story: Kafka Asagiri, art: Harukawa 35), animated in 2016. A prime example of "official work killing fanfiction."