So I was scrolling through the Golden Kamuy wikia the other day and it had like organized the characters into which group they were loyal to (HIjikata’s, Tsurumi’s, Sugimoto’s) and I noticed that Ogata was listed under every group because he had at one point or another been part of that group.
I wasn't able to make it to his Hakuouki versions birthday so I aimed for the real-life versions birthday
Also, a fun fact the real-life Izuminokami Kanesada goes up on display every year on Hijikata's birthday so it makes sense for the Shinsengumi Toudan and Chizuru Saniwa to throw a party for him
I imagine Kane-san and Horikawa made him the hat and that Chizuru cooked all the food with the help of Horikawa and Kasen