Hiro Kuroi

Hiro Kuroi (黒井ヒロ Kuroi Hiro) is the younger brother of Mato. He appears only for a few seconds in the OVA and thus, is not given enough screentime to present more information.

Appearance
Hiro, like his mother, has short brown hair and blue eyes. He is seen wearing a blue rugby shirt and dark green shorts. Naturally in being a little brother, his short stature is more apparent than Mato, during dinner he is sitting on cushion as to be level with the table.

Trivia

 * Despite little screentime interaction the siblings seem to have the typical stubborn relationship with one another. When Mato's mother tells her to wake up Hiro, Mato moans in protests but does so, stating that Hiro never listens to her when she tries to wake him up. Her mother simple says Onee-chan.
 * To wake up her brother she just opens the door and gives the order that school started that day, when Hiro doesn't respond she states that its not her fault if he is late and upon leaving gives him the raspberry.
 * After Mato leaves Hiro awakes (somewhat) and stares at his alarm clock, only to collapse into a sleepy heap.