Let's start by simply saying that everyone has to hand write at some point in their live and that every Army loves BTS and, of course, BT21. If you mix these two ingredients together you get what we have named Pens with fun! Meaning pens, but not only (more to come really soon) with the lovely characters of:

Tata - the huge heart-headed character, is an alien with transforming powers.
Koya - a smart sleepyhead, especially bright and talented, with removable ears and a purple nose
RJ - a kind and loving character, who is also a foodie since he loves cooking and eating.

Shooky- a mini prankster with a badass attitude, that loves jokes very much.
Mang - a mystery dancer who keeps his face hidden by wearing a mask.
Chimmy - the playful puppy
Cooky - a muscular Rabbit with a tough attitude, that works out a lot and can transform into a huge muscle man when he gets angry
Van - the guardian space robot who protects BT21, and said to represent ARMY.

Now, school seems a little bit more fun, doesn't it?