Hayato Hitachiin (常陸院 隼人 Hitachiin Hayato) is a supporting character who only appears in the manga. He is the husband of Yuzuha Hitachiin (a successful fashion designer whose surname is used by the entire family) and the father of Hikaru Hitachiin, Kaoru Hitachiin and Ageha Hitachiin. He works for a computer software developer.
Hayato is seen to be a level-headed and loving father who can always tell the difference between his sons. However, on a personal level, he has a weak presence and is easily overlooked by people. During their first meeting, Haruhi Fujioka assumes him to be a sort of ninja because despite being around them the whole day, he wasn't noticed at all.
- The name Hayato means "falcon" (隼) (haya) and "person" (人) (to).
- Hayato's surname Hitachiin means "always" (常) (hi), "land" (陸) (tachi) and "hospital" (院) (in).
- (To Haruhi in Chapter 45) So, Fujioka-san, you can distinguish them. For a long time, me and my wife were busy... It resulted in these two developing lonely feelings. Because of that, from their normal brother's mutual affection they became highly dependent on each other. Their desire of being recognized is strong. They isolated themselves from the others because they were afraid, these two children.