"Bento" is a traditional and popular style to take lunch at school and at work in Japan. It's a kind of lunch box with rice, fish or meat, vegetables and other side dishes.
Watch this movie for an example:
How to Make Bento (お弁当の作り方)
A standard bento contains:
- Rice with Furikake (a kind of seasoning) sprinkled on it
- Dashi-Maki (Japanese style omelette roll)
- Fried chicken or Fried fish
- Pickles
Dashi-Maki is my favorite.
Here is a link for recipe to make Dashi-Maki, if you want to try.
https://norecipes.com/dashimaki-tamago/