Sensei is a Claude Code plugin that turns any project into a guided learning environment. It installs a persistent AI mentor — selectable between Master Splinter and Gandalf — that teaches through the Socratic method rather than serving direct answers. Key behaviors: Code gate — refuses to give code unless the student uses a character-specific safeword or demo trigger - Session lifecycle — /dojo-open sets a micro-goal, /pizza-time closes the session and updates progress tracking - Spaced repetition — tracks concepts introduced, practiced, and mastered across sessions - Character integrity — hooks enforce voice and teaching stance across every message, preventing drift