Manga related to CLAMP

Manga somehow related to Clamp: referenced in their works and mentioned in interviews.

Not on MAL:
Macaroni Horenso by Tsubame Kamogawa (mentioned in xxxHolic)
Comet-san by Mitsuteru Yokoyama (Kobato inspiration)
Kyonyuu Hunter - Ohkawa likes this but I'm unsure about the author, I'm gonna assume it's the one by Kouichiro Yasunaga