RPG Heirs of the Kings is an iPhone game developed by Kotobuki Solution Co. Ltd. It is a captivating story of destiny and encounters between those with the blood of rulers. The game follows the journey of Laura, a girl who has lost her memory, and Grant, a young man who becomes separated from his father while trying to protect Laura.

One of the main features of RPG Heirs of the Kings is the ability to strengthen abilities with Soul Maps. Each character has their own unique Soul Map, allowing players to select and strengthen abilities as they desire. Soul maps expand alongside character growth, giving players the freedom to develop their party members' abilities as they see fit.

The game also offers weapon customization and arenas for players to test their strength. Collect materials to customize your weapons and challenge yourself in one of the Arenas.

In addition, RPG Heirs of the Kings features a theme song sung by Eri Kitamura, a well-known voice actor in Japanese animation.

Overall, RPG Heirs of the Kings is a free game that can be played in its entirety without the need for in-game transactions. With its intriguing storyline, customizable abilities, and challenging arenas, it offers an immersive gaming experience for RPG enthusiasts.