First Move

 First Move (最初に移動, Saisho ni idō) is the 4th chapter of Volume three and 20th chapter overall.

Plot
At To-Oh University, L challenges Light to a friendly game of tennis. Light wonders if L is planning to analyze him by observing the way he plays tennis. Meanwhile, L believes that this is just a simple tennis match, however he can’t rule out the fact that Kira hates losing. L tries a cheap first move and tells Light, “He who moves first always wins.” Even though Light is now determined to win this match, he wonders if it’ll make him seem like Kira if he’s adamant about winning. However, he notes that losing the match would make L think that Light was trying too hard to lose the match so that he wouldn’t be suspected as Kira.

A crowd gathers around the intense tennis match. They both think about their next moves. Light plans to have L tell him as much about the Kira investigation as possible so that he could decrease the risk of blurting out things only the real Kira would know. L plans to bring Light closer to him so that he could thoroughly investigate him.

Light wins the tennis match and invites L to get some drinks. L, however, reveals to Light that he suspects that he may be Kira.

Conception
The chapter's title "First Move" refers to the scene in the chapter, describing that the person who makes the first move wins. After Light wins the tennis match, he invites L to drink some tea. Ohba said L then "makes the first move" as he needs to tell Light something before they drink tea.