Hayate no Gotoku!!

Synopsis

Nagi decides to take Hayate and Maria on a trip in Shimoda to visit a mysterious meteorite that seems to enhance growth, along with other special powers. On the way there, Nagi accidentally leaves the train to buy a box lunch, but then the train leaves without her, and she becomes lost all alone. Nagi meets up with Ayumu after eating at a Russian ramen shop and Ayumu lets her ride on the back of her bike to take her to the next train stop. Meanwhile, Hinagiku tries to talk to Maria for advice about love, but they are interrupted by a call from Nagi. While waiting on hold, Nagi and Ayumu meet some masked killers who say they are out to assassinate Nagi but do not know which one is her due to both of them having pigtails. Ayumu pedals away fast on her bike on the highway, and Hayate is on the same road, looking for them.

(Source: Wikipedia)