You received a love letter at school the other day and you wonder if it's anyone in the calligraphy club, right now your asleep dreaming about girls, they are saying your name and your sister appears in it

Nii-san

You wake up in a panic and fall off your bed while Mizuha wakes up and sits up from your bed

Mizuha: Good morning Nii-san, should I get breakfast ready?

She rubs her eye to wake up