"Blood is Thicker Than Water" is the fourth episode of Durarara!!x2 Ketsu and the fifty-sixth episode overall of the Durarara!! anime.
Chikage Rokujou approaches the Yellow Scarves, intent on finding the culprits behind Kyohei Kadota's hit-and-run and the recent attack on Toramaru. Masaomi Kida, though perplexed, accepts Chikage’s challenge to a duel. Meanwhile, Anri Sonohara is shocked by recent revelations concerning Saika, and a certain proposal from Kasane Kujiragi. The plot thickens when Kasane pays Celty Sturluson and Shinra Kishitani a personal visit.
adapted from what manga or LN chapter?
references to previous episodes?
In order of appearance (not including OP)