I did this based on this scene from episode 11: https://streamable.com/oq226r

Comrade Kiui is FtM.

Not only that but his name "Watase" splits into "Wata" which means "crossing" or "ferry," often used in Japanese names to imply traversing a river or similar feature, hinting at transitions or change. While "se" meaning "rapids" or "change" is also another blatantly huge clue.

I haven't worked out what Kiui might reference, it's written in Katakana and some think it's the Kiwi bird. I don't know if this is related or not, someone else might.