Be Like Munetatsu - Black LabelAfter starting stage 1, hit enemy's bullet or enemy itself within 10 seconds.
So in short, get hit as soon as the game starts. As the achievement name suggests, only Black Label and Black Novice modes seem to be able to unlock this achievement.
You can do this in Black Novice, but Black Label is easier. Because in Black Novice, Auto Guard feature automatically prevents hits for the first several seconds.
Modes able to unlock this (confirmed): Black Label, Black Novice
Modes unable to unlock this (supposed): All other modes.
* Changing setting in OPTION -> Game Config disables all achievements.
* Using Restart from pause menu disables all achievements in that play.
Related Achievements (Published Monthly on the 30th: Continue for 30 times)
NOTE: Irrelevant to unlocking this achievement, Munetatsu is the chief editor of Famitsu Xbox 360, a Japanese magazine specialized in Xbox 360. He also has another achievement with his name. The following achievement

The Be Like Marty achievement in Halo 3: ODST worth 19 pointsIn Firefight, finish a full round without killing a single enemy. was translated in Japanese as "Be Like Munetatsu". That's the source of this achievement's name.