You can't go back to school without a bag to school! I guess your bag is one of the most important thing to take with you when you go to school, besides your books. But what would you do with your books if you got nothing to put them in? It wouldn't be handy to carry your bag in your hands all day long. Your bag can also be a nice accessorie to finish your look!
The bag I've bought for this year is a simple black one by Bershka. It is totally not an expensive one, so you can buy another one if you like. Because it's a black bag, you can wear it with every look. The bag doesn't look too big, but there is enough space for all my books, phone and all my other junk. A bag is also very important to me.
Every time I go out I take my bag with me! It's super handy and I actually don't feel compleet without one. I always put my phone, wallet, deodorant and a bottle of water in it and I can't carry all of that in my hands. So a bag is not only handy for school, you can use it every time you go out and it's also a nice accessorie and a bag tells more about you than you thing. ☺