>>114297They are technically the same character, or more accurately Oshino Shinobu is what is left of Kissshot after the events of Kizumonogatari. In Bakemonogatari, she starts off as a nameless former-vampire in the body of a small child and grows from there into her new identity.
OP's pic is of Kissshot in her prime, which you only see in flashbacks in Monogatari Second Season or in Kizumonogatari.
