騎士的公主養成：Idle Princess is a free adventure game developed by Poseidon Games for Android devices. The game takes you on a journey to a different world where you play as a knight who is summoned by a mysterious voice to save the world. The game has a Japanese-style animation with Spine 2D illustrations by popular Japanese illustrators like "Takuya Fujima" and "Ogipote."

The game features over 35 beautiful fairy companions that you need to train and raise to fight against the dark forces in the game. The turn-based combat system allows you to level up and upgrade your characters without worrying about the hassle of fighting monsters. You can also invite your friends to join you in defeating the world boss and purifying the dark fairy. The game has a free-to-play model with in-app purchases for virtual game currency and items. Please note that the game is rated 15+ due to its content involving tobacco, alcohol, sex, and mild violence.