Edit in JSFiddle

<div class="demo demo4">
  <div class="heading">毎朝ちゃんと飲むUX</div>
</div>

.demo {
  width: 500px;
  margin: 0 auto;
  padding: 10px 0;
  font-family: sans-serif;
  font-size: 20px;
  color:#3cb3e4;
}
.heading {
  margin: 10px 0
}
.demo4 .heading {
  padding: 15px 5px;
  margin: 10px -20px;
  border: solid 3px #3cb3e4;
  position:relative;
  text-align: center;
  border-radius: 3px;
  background: #fff;
}
.demo4 .heading:after,
.demo4 .heading:before {
  content: '';
  position: absolute;
  bottom: -7px;
  background: #3cb3e4;
  border: solid 2px #3cb3e4;
  width: 25px;
  height: 20px;
  z-index: -1;
}
.demo4 .heading:after {
     left: 2px;
     transform: rotate(120deg);
}
.demo4 .heading:before {
    right: 2px;
    transform: rotate(60deg);
}