I solved the issue. Problem was my vue-onsen-components.js file. I removed the comment of

export { default as VOnsInput } from 'vue-onsenui/esm/components/VOnsInput'

<template>
  <v-ons-page>
    <toolbar :title="msg"></toolbar>

    <v-ons-card>
      E-Posta
      <v-ons-input placeholder="E-Posta adresiniz"></v-ons-input>
    </v-ons-card>

  </v-ons-page>
</template>

<script>
  import Toolbar from './layout/partials/Toolbar'

  export default {
    components: {Toolbar},
    name: 'login',
    data () {
      return {
        msg: 'Giriş',
        inputEmail: '',
        inputPassword: ''
      }
    },
    methods: {}
  }
</script>

That’s the result:

Dependencies

"dependencies": {
    "font-awesome": "^4.7.0",
    "onsenui": "~2.8.2",
    "vue": "^2.5.2",
    "vue-onsenui": "~2.4.2",
    "vue-router": "^3.0.1",
    "vuex": "^3.0.0"
  }