This page explains how to recruit Leena in Chrono Cross: The Radical Dreamers Edition.
Leena is Serge’s childhood friend, who lives in Arni Village.
How to Recruit¶
You only get one chance to recruit Leena, near the beginning of the game, and it’s extremely counter-intuitive. When you first arrive in Another World and after defeating Karsh, Solt and Peppor at Cape Howl, Kid will ask to join your party. Decline Kid’s request by picking the bottom option three times.
The next day, Leena will decided to accompany you to Termina, alongside Poshul if you didn’t recruit her earlier.