|Japanese||松永 葵（まつなが あおい）|
|Family|| Akane Matsunaga (Sister)|
Seiji Matsunaga (Uncle)
Kouichi Matsunaga (Father)
Misaki Matsunaga (Mother) †
Aoi is much more thoughtful and serious than his sister. When he is in trouble or injured, he has a tendency to cry and sulk. Occasionally, Aoi will say something intelligent well beyond his years, but can only understand so much of adult speech. Aoi has also expressed an intention of marrying Shiharu, although he does not understand the meaning of marrying somebody.
Aoi has wavy blonde hair and brown eyes. One way to differentiate him from his twin sister, Akane, is to see that his bangs are much longer than hers.
The twins' mother, Misaki, died in a car accident. The death of his wife left Kouichi Matsunaga in a state of shock. Kouichi asked his younger brother Seiji to look after Akane and Aoi while he took care of his wife's funeral. After the phone call, Kouichi disappeared. Since then, the twins were left under Seiji's care.