This episode dived into Koito’s backstory. It perfectly illustrated why Ogata called him a spoiled brat. But also why he admires Tsurumi as much as he did. Though the execution of it seems odd. Tsurumi is the only person who could aid the search for Koito. The anime even focuses on the words that the Russian says, Barchonok, in which the delivery is the same as Ogata’s.
At the very least it is clear that Koito’s father was unaware of it. Even more so, there is a clear focus to make Tsurumi the focus rather than having the focus be the father and son being reunited. If this happened before Tsukishima’s backstory, there could be some doubt, but clearly the intention is that Tsurumi set it up. Tsurumi getting a connection with Koito’s father and Koito himself not even being aware that he is being taken advantage of. Unlike the case with Tsukishima & Ogata, because they know what Tsurumi is actually doing.
This episode covered the last of the skipped content from volume 20, that being chapters 197-200.