Eternights is a 2023 dating sim action role-playing game developed and published by Studio Sai.

Hitting an enemy enough times within a short period creates a combo, allowing the player to perform a stronger attack or a finisher.

An anti-aging drug called Eternights mutates people into monsters, and supernatural events begin to occur.

An 18-year-old boy (who is named by the player) is attacked by an unknown woman named Delia who cuts his arm off using her scythe, and another woman he met on a dating app replaces his lost arm with a magical, glowing one that can also transform into a sword, allowing him to fight the monsters.

[12] Before release, Eternights drew comparisons to the Persona video game series due to its premise of teenagers fighting supernatural enemies while including social and calendar elements in the gameplay.