Mami Koizumi, a 28-year-old homeroom teacher at Oribe Academy, advises the pottery club with a carefree approach. Born on December 12 and blood type B, she sports short blue hair cropped to her ears and steady gray eyes. Her casual demeanor extends to her teaching style, where she often sidesteps formal responsibilities in favor of reading manga or playful banter with students like Naoko Naruse. As a mentor, she offers minimal direct guidance, encouraging club members to experiment freely with pottery at their own pace. Content to maintain a consistently relaxed atmosphere, she prioritizes fostering student autonomy over structured oversight.