This book is like a more scifi version of Crier's War, so of course I loved it. Sona and Eris both own my heart. I don't know who I want to be with more and who I want to be more. That cliffhanger was intense, unfortunately I'll have to wait for the next book. The premise also reminds me a bit of Iron Widow, so maybe if you enjoyed this you would enjoy that and vice versa. 
You can tell that this is a debut novel, but it's still pretty good. Can't wait to see what else Mikuta writes! She's definitely got potential.