This story is gritty and dark at times. However if you want to understand the main character more I suggest you read these two before reading this one: Tadayoedo Shizumazu Saredo Naki Mo Sezu #2 Don't Stay Gold. Those two give you a history of Yashiro what happen in his life to make him act this way, plus you will understand his longtime friend and doctor.
Saezuru Tori wa Habatakanai