Being the oldest, Touya was typically the one who cared for his siblings when they were sick. Colds and general illnesses were uncommon in the household, Half of the family were tolerant enough to the cold to not get many sicknesses, And the other half ran hot enough to burn out most common illnesses. But, of course, since Enji was busy with Shouto, when you got sick one day, Touya was the one caring for you.