Damn this series can easily goes to dark path of tragedy but the creator seems to really avoid that.
I wont be surprised if Chiya's grandmother is actually a foster parent of both Chiya and Sharo, whos their parent dies in a war (the same war where chino's father and rize's father fought).
Man this series does better in 4 chapters and an epilogue than many do in 20 + 2-3 specials. Not particularly fair in all aspects since the longer series have more plot and work to handle, but still this one gets 'er dun.
Still waiting for the day when I find a good and healthy yandere relationship. Good ole' infamous Yuno was pretty close but not quite there.
if you seek some healthy yandere relationship, try koharu no hibi. but not a yuri tho