Other Mangaka Takeuchi Naoko Knows

Hiura Satoru (Angel Blue and Paradise Cafe)

Ichijou Yukari (Shojo manga artist) (she calls her Queen)

Yoshizumi Wataru (Marmalade Boy)

Itou Takehiko (Outlaw Star)

Hara Tetsuo (Hokuto no Ken)

Shibata Ami (Jiyuujin Hero)

Watsuki Nobuhiro (Rurouni Kenshin)

Fujishima Kosuke (Aa! Megami-sama!)

Watase Yuu (Fushigi Yuugi)

Nekobe Neko (Goldfish Warning)

Miwa Ueda (Peach Girl... Miwa worked as an assistant for Takeuchi-sensei for a while..)

Matsumoto Reiji (Space Crusier Yamato, the person who inspired her to be a mangaka. ^_^ She has lunch with him. [Source: Official Site])

Togashi Yoshihiro (Yuu Yuu Hakusho and HunterxHunter) (you thought I'd forget him HA!)

(probably others too, that I'm not aware of, have any leads, and your proof, tell me, and I'll add them)