If I remember correctly, you should meet him first in the Malediction class (either on Wed or Thu you can check it in the guide) After the first event there would be 4 events which happen in the library, forest (lunch) , kitchen or garden, some requires you to play truant. Honestly, just choose the option that seems pleases him the most and lengthen your conversation. After you finish 5 events you wont find him anywhere but worry not, it still leads to his success ending.
Goodluck mate !