Narutaru: Mukuro Naru Hoshi Tama Taru Ko

"From a dying planet shall come the children of light..."

While on vacation on a small island, young Shiina Tamai dives under the water near an old shrine and discovers an unearthly starfish-like creature. She nearly drowns but is rescued by the silent, wide-eyed little animal, who Shiina befriends and names Hoshimaru. To Shiina's surprise and delight, the creature changes shape, lets Shiina stand on him, and the two fly off into the clouds. But what looks to be a young girl's ultimate fantasy soon takes a darker turn as Shiina and Hoshimaru become entangled in a struggle between rival extraterrestrial factions who battle in the skies upon huge alien beasts called Shadow Dragons, with the fate of Earth hanging in the balance.

(Source: Dark Horse)

Narutaru: Mukuro Naru Hoshi Tama Taru Ko was first published in English as Shadow Star☆ by Dark Horse in the magazine Super Manga Blast from September 13, 2000, to February 1, 2006—issues 5 to 59, which was the final issue. The manga was partially published in standard tankoubon format as well by the same publisher, with seven volumes published from September 5, 2001, to December 21, 2005.