JSFiddle - React, Tailwind, and code Playground

HTML

<div class="frame">
<span class="test test2">qwerty</span>
</div>

CSS

.frame{
	height:200px;
	width:200px;
	border-style:solid;
	border-width:3px;
}

.test2{
	opacity:0;
}

JavaScript

$('.frame').on('mouseenter', function() {
	var el=$(this),
	if(el.type == mouseenter){
		el.find('.test').removeClass('test2');
	}else{
		el.find('.test').addClass('test2');
	}
});