<div class="character-box">
  <h1 class="character">耐久</h1>
  <span class="border  border--top"></span>
  <span class="border  border--right"></span>
  <span class="border  border--bottom"></span>
  <span class="border  border--left"></span>
</div>
body {
  display: grid;
  place-items: center;
  min-height: 100vh;
  background-color: #000;
}

.character-box { 
  position: relative; 
}

.character {
  display: inline-block;
  margin: 0;
  padding: 48px;
  color: #fff;
  font-size: 4rem;
  cursor: pointer;
}

.border {
  position: absolute;
  background-color: #fff;
  transition: all 800ms cubic-bezier(0.86, 0, 0.07, 1);  
}

.border--top,
.border--bottom {
  width: 0;
  height: 2px;
}

.border--right,
.border--left {
  width: 2px;
  height: 0;
}

.border--top {
  top: 0;
  left: 0;
}

.border--right {
  top: 0;
  right: 0;
}

.border--bottom {
  bottom: 0;
  right: 0;
}

.border--left {
  bottom: 0;
  left: 0;
}

.character-box:hover .border--top,
.character-box:hover .border--bottom { width: 100%; }

.character-box:hover .border--right,
.character-box:hover .border--left { height: 100%; }

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.