Encounterdeath Note : Season 1 Episode 9 «FRESH — Collection»

Light is forced to maintain a calm exterior while internally spiraling into a panic. He realizes L has trapped him in a perfect "checkmate" scenario:

To further pressure Light, L invites him to join the investigation, hoping that closer contact will eventually force a slip-up. Key Themes & Analysis Encounter | Death Note Wiki | Fandom EncounterDeath Note : Season 1 Episode 9

If Light tries to kill "Hideki Ryuga" using the Death Note, he would likely picture the famous idol instead of the person in front of him, resulting in the idol's death and confirming Light is Kira. Light is forced to maintain a calm exterior

Light is forced to maintain a calm exterior while internally spiraling into a panic. He realizes L has trapped him in a perfect "checkmate" scenario:

To further pressure Light, L invites him to join the investigation, hoping that closer contact will eventually force a slip-up. Key Themes & Analysis Encounter | Death Note Wiki | Fandom

If Light tries to kill "Hideki Ryuga" using the Death Note, he would likely picture the famous idol instead of the person in front of him, resulting in the idol's death and confirming Light is Kira.