おとうとグランプリ is a simulation game developed by 株式会社 WHRP. The game allows you to play as a big brother or big sister and take care of three young boys, guiding them to compete in a grand prix. After returning to the countryside after several years, you are surprised to find that all the boys you encounter are your younger brothers!

The game features over 40 different storylines, including multiple endings. Each brother has their own unique personality, ranging from mischievous to cool and laid-back. You can spend your days with them, enjoying various activities such as teaching them songs and dances, giving them presents, and nurturing their growth.

With easy controls and the ability to play in your spare time, おとうとグランプリ is a game that can be enjoyed on the go. Strengthen your bond with your brothers by petting them and deepening your family ties. Join forces with your brothers and aim for the grand prix to make your town proud!

Please note that the game is only available in Japanese and is compatible with both Android devices. It is free to download and play.