Oh that would be really fun, I haven't gotten to play that side of her much! Shisui in s1 has. so many issues. She is going to be speaking about none of them <3. But having a confidant who isn't going to rat her out would genuinely be immensely helpful for her. Honestly torn about whether or not she knows about Hiroe's secret because on one hand, if Hiroe is willing to help Shisui out with her plan, then the degree of her internal conflict would lessen significantly, especially if she knows Hiroe will be safe and she won't have to involve anyone else. However, the depth of her internal conflict....how about the best of both worlds and have a reveal happen somewhere along the line? Maybe around season 1's end. What reason do you want Hiroe to have to be Shisui's lady in waiting? Like, is it for a specific reason such as they're prior friends or just generally? Shisui probably won't reveal anything unless she's known Hiroe for a while, but playing that out would be fun on its own too.

Oh, how'd you find season 1 by the way? I could get more detailed with where to go with this, but that would involve heavy season 2 spoilers pertaining to Shisui if you're okay with that? I can be really vague if its not, though a lot of Shisui's character relies heavily on season 2 revelations and events.