"Ballpoint Pen" Gel Pen with Monchhichi Mascot Twins by iPlanning. This gel pen features a cute rubber mascot. Another adorable new addition to the globally popular Monchhichi line is this black gel pen with a light, comfortable writing feel. The pen barrel design and rubber mascot are adorable. There are plenty of cute stationery options, so be sure to find one you like. Size: Approx. 12 x 150mm diameter (pen). Perfect for writing instruments, stationery, school supplies, and study.