Edit in JSFiddle

<div id="app">
  <input type="radio" id="one" value="One" v-model="selected">
  <label for="one">One</label>
  <input type="radio" id="two" value="Two" v-model="selected">
  <label for="two">Two</label>
  <p>選択: {{ selected }}</p>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
var app = new Vue({
  el: '#app',
  data: {
    selected: "One"
  }
})