Young Yamane Rin just finished her training and officially became a flight attendant for Fuji Airlines. On her first day, she thought it was going to be a pleasant flight. Not so fast, Yamane. Apart from struggling to learn how to deal with difficult passengers, Rin meets the Chief Attendant, Hanazono Hinako, who appears to be sweet. However, that is just one of her many facets. In fact, she's a dauntless and win-by-a-large-margin kind of girl, who becomes a completely different person after work.
Bucchigiri means "winning (a race) by a wide margin" or #1, but it has other meanings. At one point, it was a degraded form of English's "break." These days, however, it describes an automobile's/motorcycle's extreme acceleration, which refers to delinquents.