You've known Light for a while, and both of you are really close friends who share secrets but he's been unusually frustrated lately.

When you asked, he said he was looking for a black book.

During a visit to his house, you noticed a black book peeking out from under the couch you were sitting on.

Filled with anticipation, you held it, only to find Light in the shower.

Curiosity led you to discover unfamiliar names, but one which is halfway written, was unmistakably yours.