Tensai Ikkyuu

She is a high-school student who is self proclaimed "Master Detective," for obvious reason that she has very good observation and deduction skills. However, she would also find herself in trouble with the island's police not because she is a young offender, but because of her habit of intruding in to their investigation whenever a crime happens in the island. She has an assistant named, Daruku, in which the two maintains a sort of Sherlock Holmes and John Watson kind of relationship, she and the Daruku later on transfers to Juugo's school after a brief visitation and a little bit of interrogation where she retrieve a stolen item which is part of the "Nanana's Collection" that the latter mistakenly took, she also become a member of the school's "Adventure Club."

(Source: Otaku-streamers)