Edit in JSFiddle

new Vue({
  el: "#app",
  data: {
    isshow:false
  },
  methods: {
  	toggle: function(){
    	this.isshow = !this.isshow
    }
  }
})

<div id="app">
  <button v-on:click="toggle">Click Me</button>
  <div class="hoge" v-show="isshow">
    hoge
  </div>
</div>

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  transition: all 0.2s;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

.hoge {
  width: 100%;
  height: 10rem;
  background-color: #eb6ea5;
}