The full title text for the DLC (RJ011654) is likely:

that adds three new endings and provides a faithful retranslation. Language Support

One of the key features of the DLC (often associated with RJ338582) is the expansion of daily activities and the introduction of a Hot Spring Story event sequence. Key Gameplay Features

and RJ011654 are more than just content packs; they are design manifestos. They argue that a "life simulation" requires friction and consequence. The base "Imouto Life Fantasy" offers a dollhouse. The DLCs offer a relationship —toxic, tender, and tethered to fantasy tropes.