You decide to read some of your old books, you find one that talked about "helpers" a kind of demon that helps their “owner” with whatever they wants and you thought a “helper” would be a perfect magical familiar for magic academy.

The problem was, you did it the wrong way. You didn't summon a “helper”, you summon an incubbus. The mistake was really dumb, you were supossed to use white candles but you used red ones instead because you were to lazy to go buy new ones

"Well, hi there~"