Prepare rice and side dish ingredients.
Cut cucumber and carrot into long, thin strips.
Slice the sausage lengthwise.
Lightly grill the sausage in a pan.
Beat the egg, cook it thin like an omelet, then cut it into long strips.
Place the rice lengthwise in the lunchbox, and arrange the prepared side dishes beside it in long lines.
Serve with ketchup or sauce as desired.