hiraeth [ishigami senku]

Once upon a time, your problems were as simple as getting your homework done before the deadline, trying to hide your feelings from the person you admired, and deciding what to eat for dinner. Now, your problems consisted of doing your best to survive for a day longer in an unfamiliar environment, living in a world devoid of modern technology, and planning a way to escape from Tsukasa's empire.

Oh, wait. One problem remains unchanged.

(Obviously, it's deciding what to eat for dinner.)