Doutou no Saikyou Senshi Suima-kun

Welcome to planet Goo, home of the Suima Clan, tall beings that need 23 hours of sleep a day or they become weak.

Unfortunately, Goo's ruler, Prince Brillian, has been overcome with a mysterious insomniatic illness! The sexually robust and dazzlingly handsome General Ketsukarl must collect 1000 people's worth of 'Sleepy Sleep' energy to return the prince to his normal sleeping patterns!

Join General Ketsukarl on his frantic, crazy search in this hilariously sexy(?) comedy!

(Source: Manga Reborn)

Note: The digital version splits the original chapters, so the chapter count differs.