Geass vs. Geass
Lelouch believes Shirley may have discovered his identity as Zero, so he and C.C. pursue her to Narita. Ohgi explores the battlefield of the previous night, discovering the wounded Villetta Nu left for dead out of sight. Lelouch encounters Mao, a young man who also has the power of Geass. Mao uses his mind-reading power to play on Shirley's insecurities, manipulating her into shooting Lelouch, but she falters at the last moment and C.C. sends Mao away temporarily. Since Shirley is being torn apart by grief and guilt, Lelouch uses his Geass to erase her memories of him.
Aired 19/01/2007EP 14 - Geass vs. Geass

Code Geass: Lelouch of the Rebellion
On August 10th of the year 2010 the Holy Empire of Britannia began a campaign of conquest, its sights set on Japan. Operations were completed in one month thanks to Britannia's deployment of new mobile humanoid armor vehicles dubbed Knightmare Frames. Japan's rights and identity were stripped away, the once proud nation now referred to as Area 11. Its citizens, Elevens, are forced to scratch out a living while the Britannian aristocracy lives comfortably within their settlements. Pockets of resistance appear throughout Area 11, working towards independence for Japan.
Lelouch, an exiled Imperial Prince of Britannia posing as a student, finds himself in the heart of the ongoing conflict for the island nation. Through a chance meeting with a mysterious girl named C.C., Lelouch gains his Geass, the power of the king. Now endowed with absolute dominance over any person, Lelouch may finally realize his goal of bringing down Britannia from within!
(Source: Bandai Entertainment)