Manga based on the BL game developed by Alice Blue. Each storyline has a different author:

Prologue: AKIRA Norikazu
Kurosaki x Higuchi: AMAGI Reno
Kurosaki x Shimizu: IKE Reibun
Kurosaki x Yamaguchi: SAKURA Ryou
Kurosaki x Yoshioka: TAMAQUIS Wren
Yoshioka-centric gag shorts: KYUUSHUU Danji

From Aku-tenshi: In a peaceful farmland country, there lived a prince Canaan who yearned for adventures. Together with his personal bodyguard Celeste, the ultimate adventure awaits~! Guilds, dungeons, and... Hot springs!? Based on the ever so popular BL RPG game made by Alice Blue, Oujisama Lv.1