>>531157986
Shupo is Japan's onomatopoeia for the noise a train makes. Nozomi - the twintails one - can be seen saying シュポ シュポ = shuposhupo in the second panel on the right. Gaki comes from mesugaki. Definition from Jisho.org.
>メスガキ
>Noun
>1. cheeky, vulgar brat; impudent young temptressSlang, Vulgar expression or word