"俺の妹とこんなにラッキーなイベントはない" is a free simulation game developed by Team Moko App. It offers players the chance to experience lucky events with their tsundere little sister.

The game allows you to choose different locations within your house, where lucky events may occur. By increasing your luck level, you can unlock new locations and progress in the game. As you level up, you'll notice a change in your sister's behavior, from tsundere to tsundere.

The gameplay is simple and involves selecting locations and engaging in conversations with your sister to increase your luck level. The conversations vary depending on the content, and the luck level affects the dialogue and your sister's mood.

Please note that the difficulty level is set to "high," and the lucky events have a soft and lighthearted feel.

If you're looking for a short and casual game to play in your free time, "俺の妹とこんなにラッキーなイベントはない" could be a fun choice.