datsu-sara jujutsushi no Nanami-kun deesu 脱サラ呪術師の七海君でーす [He] is the ex-salaryman curse-technique-master Nanami-kun!
jujutsu 呪術 means literally "curse," noroi 呪い, "technique," jutsu 術, and ~shi ～師 is a suffix that means "master," as in someone who has mastered techniques in the study of something.
Normally jujutsushi would translate to "witch doctor" or "shaman," who use curses on people, like straw dolls, but in this series the translation "sorcerer" is also used, even though a magic sorcerer would be a majutsushi 魔術師 instead.
sono iikata yamete kudasai その言い方やめて下さい Please stop with that way-of-saying. (literally.) Please stop calling me that, introducing me like that, etc.
