I was lost on this one. .

Me too ^^;

Cuz this is the last book. U need to read the prequels

May I know the prequel? .plaese share the link. .（＾Ｏ＾）

When he is first mentioned. He is sorta the villain.
http://www.mangago.zone/read-manga/kanashii_kotoba/

Second story is about him starts around chapter 4
http://www.mangago.zone/read-manga/nemurenai_koibito/

Start at chapter 3
http://www.mangago.zone/read-manga/chizuka_san_ni_tsutaete/

Then this book is the last one

Thanks. .