Starting this year, all Nintendo games rated CERO C and up (that’s 15+) will be packaged with black boxes.
Nintendo announced the change shortly before the release of Zangeki no Reginleiv, Nintendo’s first “M” rated (well, M equivalent) game in Japan. Previously, CERO C (15+), D (17+), and the rare Z (18+) used standard white covers. CERO C games include Ghost Squad, Disaster: Day of Crisis and WWE 2008 Smackdown vs. Raw. Onechanbara: Bikini Zombie Slayers, No More Heroes, and currently every Resident Evil game on the Wii are examples of CERO D titles. Madworld, which Spike is publishing in February, is the only CERO Z game.
The black boxes are meant to be another warning for parents, on top of the colorful CERO labels on the spine and the CERO stamp on the cover. This packaging may actually have a benefit too since these games will standout against the basic white box art.
So far, Nintendo is the only company to do this. CERO C and even heavily restricted CERO Z games are not required to have different boxes or covers in Japan.