Henji is a macOS app that turns a quick scribble into a polished reply written in your usual voice across messaging and email channels including Slack, LINE, Gmail, and Messages. Rather than producing generic, templated AI text, it adapts tone to the context, offering modes such as Polite, Casual, Team, and Friends so internal threads stay fast and personal messages stay warm. The more you use it, the more it learns to sound like you, and it can handle nuanced situations like politely declining a request or negotiating a deadline. Henji supports multiple languages including English and Japanese and is downloaded as a native Mac application.