3: Do they exercise, and if so, what do they do? How often?
Hiroki was never good with sports— mainly because he was never interested in them, but he has developed an habit of going to the gym on an almost daily basis.
5: Cleanliness habits (personal, workspace, etc.)
Hiroki is as clean as he can be, considering the fact that most of his life was spent either between the completly dirty streets or the wonderful house (he refuses to call it mansion), and he has never bothered in learning how to clean properly. If you could rate the cleanliness from 1 to 10, my bet is that he is somewhere between 6 or 7.
15: Biggest and smallest short term goal?
Hiroki is one of those people that don't trace goals for themselves, and if they exist— they are mainly related to family work, or his quiet trips to night clubs. Usually, those goals take a long time to develop, hence he never had a short term goal (unless you count that time when he was around the age of 10, and was completly determinated to read a whole manga library in a week).
20: Childhood illnesses? Any interesting stories behind them?
He has suffered of pneumonia during almost all of his childhood years— winter was never his favorite season and he was one to blame for running around naked when it was snowing —. There aren't many interesting stories about pneumonia, considering he was forced to stay in bed for one to two weeks, Nokiro (one of the maids) being his personal nurse.
35: What activities do they enjoy, but consider to be a waste of time?
Dancing and singing. He seriously enjoys those both things, but he can't exactly bother to make them room in his schedules, knowing that they take too much time and he isn't one to waste it.