Saimin Class Wonderful ~Joshi Zen'in, Shiranai Uchi ni Mata Ninshin Shitemashita~

The protagonist is a gullible high school student living with his sister. After blowing his allowance on useless junk, he spots a magazine claiming to teach hypnosis and orders it immediately. Caught red-handed by his sister, he's forced to demonstrate its power. A magic coin fails, but a random lighter from the package sparks a breakthrough—his sister is hypnotized! Now he uses this hypnotic lighter to spice up his school life.