The following characters all play a minor role in Gravitation. Almost all of them are found only in the manga, with the exception of Maiko, who can also be seen in the OAVs.

RAGE
Rage is Shuichi's manager in New York. She's 18 years old and has her birthday on November 15. She doesn't like it when people think she's just a plain girl. XD She's got a thing for Shuichi but treats Shuichi badly. Her blood type is A.

JUDY WINCHESTER
Judy Winchester is a Hollywood superstar. XD She is a gorgeous and yet firey woman whose actions and characteristics resemble those of her husband. <_< She has a habit of smoking and wears sunglasses, pretty much the glamorous all-star Hollywood actress. She also does blackmailing and has a thing for weaponry, so she is quite a match for her husband. XDD She's 32 years old and her birthday is on september 10th. She has blood type O.

MICHAEL WINCHESTER
K's young son, Michael Winchester, doesn't appear much even in the manga. However, he's five years old and a bundle of cuteness. ^_^ He loves to be with his father, but could use a little more attention from him. From what I can see, he doesn't cause much trouble and is just an ordinary kid. :) His birthday is on March 17 and his blood type is O.

MAIKO SHINDOU
Maiko is Shuichi's sister, and she only appears in the manga and the OAVs. She's pretty cute and considerate, worried about Shuichi when he was distressed and often educating him and fooling around with him. She was the keyboardist for Bad Luck in the beginning of the manga, but was later replaced by Suguru. :D

ARK NARSEVICH
Ark is Judy's personal bodyguard, and he works only for her and is very loyal to her. Ark and K were both soldiers in the past, and he's saved K's life once. They used to communicate well, but the feeling's faded as time went on. Ark's 32 years old, has blood type AB and his birthday is May 2nd.

YOSHIKI KITAZAWA
Yoshiki is Yuki Kitazawa's younger brother. He's a male but you absolutely cannot tell by looking at him since he's a male transvestite. XD He's 19 years old, his birthday is on December 22nd and his blood type is B.

YUUJI NAKANO
Yuuji is Hiro's older brother. He wants to be an actor and he loves to eat. XD He is 25 years old, has his birthday on May 5th, and has blood type A.