Eclairisse (Japanese: エクレール Éclair) is a character of the day who appeared in A Campus Reunion!. She is a reseacher at an academy specializing in Electric-type Pokémon and was Clemont's teacher in his youth, when he studied at said academy.
Éclairisse first appeared approacing Ash and his friends, as she had recognized Clemont. She called his name, and he immediately recognized her. After introduction, Éclairisse took the group to the academy where she works and Clemont used to study and gave them a tour. After the tour, Éclairisse told the group more about Clemont's time at the academy and how he was a brilliant student. The next day, she was present when Clemont caught Luxio.