At the gate of Qingning Middle School, there is a small shop called 'Alchemy Workshop'. Although this small shop has limited supply every day, the boss who looks fierce can always come up with some new tricks— —The starry sky lollipop that can really enjoy the brilliance of the Milky Way; the multi-color ballpoint pen that can automatically cope with various exams by changing different refills; The youthful time that can't go back.