Tsujimura is an award-winning novelist, she is best known for her mystery and children novels. She studied at Chiba University and won the Naoki Prize in 2012 for Kagi no nai Yume wo Miru (I Saw a Dream Without a Key), and in 2018 she won the Japan Booksellers' Award for her novel Kagami no Kojo (Lonely Castle in the Mirror).
I think it's a 2.6 to 3 stars book. The story is okay-ish and it is definitely not boring, it's one of those books you picked up causally when you have free time and the reading won't charge you too much effort. The characters are shaped up enough and I like how their motivations are revealed to us. Like other novels by Ms. Tsujimura, I think this novel is a nice but it is not very outstanding or remarkable.