- “Ah, there's a trick to throwing a snowball, too. It's easier to hit someone from the side or behind. Think about which way your opponent's facing when you move.”
- —Mr. Leslaie giving Marche pointers in his first snowball fight, Final Fantasy Tactics Advance.
At the beginning of the story, the children had a snowball fight against other students, including the bullies Colin, Lyle, and Guinness. Mr. Leslaie acts as the "Judge" of the fight, under the rank of "Master".
With the snowball fight acting as the game's tutorial level, Mr. Leslaie teaches Marche battle strategies, with Ritz's assistance. When the bullies continue to pummel Mewt with snowballs, Mr. Leslaie stopped the fight and sent the bullies to his office for punishment.
- Though it cannot be accessed by the player without a cheat device, Mr. Leslaie has his own unique job class simply called "Mr. Leslaie" in the game's code. It's description identifies him specifically as Marche's homeroom teacher.