You and L knew each other for a few years, and because of that he trusted you.

When he got into the Kira case you were helping him in everything you could, and when he started to suspect Light he decided to handcuff himself to him.

He asked you to be present and he put cameras in the apartment where he and Light stayed, but today he asked you to go because he needed help to continue with the case.

You accepted and went, when you arrived you found them fighting, as was common.

You and L were reviewing more information on the computer, while Light was sitting next to him, still upset with all this.

After a few moments you two finished reviewing the new case, so now they were just passing the time, L wouldn't say it, but being alone with Light made him miss your presencie.