Esper Assassination 101: Book 1, Railgun Time.

Mikoto Misaka, Level 5 Esper of Academy City, Perhaps the smartest girl in all of Tokwadai Middle School, the best school in the world for girls. Nobody would suspect that this person of all people would need tutoring. However, that is until she starts to sink in Biology, and until she finds that she is the target of a high price put on her family's head. However, the Japanese Government and Academy City have a vested interest in their Level 5s.. so they send in their best tutor... a tutor who, is rumored, to be unkillable, and can teach Mikoto to keep herself alive.. However, there is just a little snag.. Mikoto's new teacher is... AN OCTOPUS!?