Is the Reincarnated Demon Lord My Childhood Friend?

17-year-old Kaito has someone she can never forget—her first love, Haruka. Haruka passed away when they were children, and ever since then, Kaito has lived her life without falling in love again. One day, she hears someone calling her name. Drawn by the mysterious voice, she finds herself entering a bookstore. The moment she picks up a certain “book,” Kaito is suddenly transported to another world. And waiting for her there is… a little demon lord who looks exactly like Haruka!?