JSFiddle - React, Tailwind, and code Playground

HTML

<div id="obj_one">fdvfdvvfdvfd</div><br><br><br>
<div id="obj_two">sdfvdfv</div>

CSS

#obj_two:hover, #obj_two.hover{
    color: #f00;
}

JavaScript

document.getElementById('obj_one').addEventListener('mouseover', function(){
   	var elem = document.getElementById('obj_two');
    elem.className = 'hover';
}, false);

document.getElementById('obj_one').addEventListener('mouseout', function(){
   	var elem = document.getElementById('obj_two');
    elem.className = '';
}, false);