かな (or tap right ⌘) types through the machine; 英数 (left ⌘) types plainly. Every henkan session starts from the starting state; ⌫ turns the rotors back. Tab picks another form; Space or Enter commits. In muhenkan, 半角/全角 (or `) enciphers the selection. Typing the ciphertext again, from the same starting state, gives back the plaintext.