Golden Kamuy | BARCHONOK | Koito Remembers Being Called BARCHONOK And Gets Suspicious About Ogata
in season 3 episode 12, when Ogata is about to flee the hospital, he calls Koitio BARCHONOK (Spoiled Brat). In season 4 episode 3 Koito asks Tsukishima what the word means and he tells him it means spoiled brat, asking him where he found that. In season 4 episode 4, we get a story of Koito being fake kidnapped by Tsurumi and his men (Ogata in them) and the masked Ogata calls Koito BARCHONOK.