王子さまLv1.5

Ouji-sama Lv1.5 is a collection of smaller games based solely on Ouji-sama Lv1. It's akin to Alicesoft Alice's Cottage.

The main game is called "Ouji-sama 1 month after" and is set one month after the events of Lv1. The story revolves around Celeste Irving's family and the conflict between Adolphe Irving and his soon-to-be son-in-law.