。
She got on the bus to Harajuku.
Literal
She [topic-は] Harajuku-bound [of-の] bus [onto-に] boarded.
原宿行き uses the suffix ~行き (read -yuki or -iki) attached to a place name, the standard wording for transport destinations: 東京行きの新幹線 ('the Tokyo-bound Shinkansen'), 成田行きのバス ('the Narita-bound bus'). 乗る ('board, ride') takes its vehicle with に, marking the means of transport one boards onto. 原宿 is a district in central Tokyo famous as the epicenter of youth fashion and kawaii culture — Takeshita Street (竹下通り) draws teenage shoppers, while the parallel Cat Street caters to a slightly older crowd, and the adjacent Meiji Jingu shrine and Yoyogi Park supply a striking contrast between pop-cultural buzz and quiet tradition.