JSFiddle - React, Tailwind, and code Playground

HTML

<span class="ko">こ</span><span class="re">れ</span>

CSS

.ko:after {
    content: "ko";
    display: none;
    top: 100px;
    left: 100px;
    position: fixed;
}
.re:after {
    content: "re";
    display: none;
    top: 100px;
    left: 100px;
    position: fixed;
}

span:hover:after {
    display: block;
}

span {
    display: inline;
}