Edit in JSFiddle

var app = angular.module('app', []);

app.controller('appController', function ($scope) {

});

app.directive('enter', function () {
    return {
        restrict: 'A',
        link: function(scope, element){
            element.bind('mouseenter', function() {
                element.html('mouseenter');
            })
        }
    };
});

app.directive('leave', function () {
    return {
        restrict: 'A',
        link: function(scope, element, atts){
            element.bind('mouseleave', function() {
                element.html(atts.leave);
            })
        }
    };
});
<section ng-app="app" class="container">
    <section ng-controller="appController">
        <div class="target" enter leave="good bye">hover over me</div>
    </section>
</section>
.target {
    width: 100px;
    height: 100px;
    border-radius: 5%;
    margin: 30px;
    padding: 20px;
    background: #00a;
    text-align: center;
    color: #fff;
}